ALMATY, Kazakhstan (AP) — Iran and six world powers failed to reach agreement Saturday on how to reduce fears that Tehranmight use its nuclear technology to make weapons, extending years of inconclusive talks and adding to concerns the diplomatic window on reaching a deal with Tehran may soon close.

Expectations the negotiations were making progress rose as an afternoon session continued into the evening. But comments by the two sides after they ended made clear that they fell far short of making enough headway to qualify the meeting as a success.

"What matters in the end is substance, and ... we are still a considerable distance apart," Catherine Ashton, the European Union's head of foreign policy, told reporters at the end of the two-day talks.

Ashton, the convener of the meeting, said negotiators would now consult with their capitals. She made no mention of plans for new talks — another sign that the gap dividing the two sides remains substantial. She said she would talk with chief Iranian negotiatorSaeed Jalili by telephone over further steps.

Jalili spoke of "some distance between the positions of the two sides." He suggested Iran was ready to discuss meeting a key demand of the other side — cutting back its highest-grade uranium enrichment production and stockpile — but only if the six reciprocated with rewards far greater than they are now willing to give.

Western negotiators noted an improved atmosphere from previous sessions, with Ashton speaking of "a real back and forth between us when were able to discuss details, to pose questions, and to get answers directly."

She described the better negotiating climate as a "very important element."

Still, the lack of forward movement in international negotiations that started a decade ago was certain to increase concerns that diplomacy was ineffective as a tool to stop Iran from moving toward nuclear-weapon making capacity.

Israel is most worried. The Jewish state says Iran is only a few months away from the threshold of having material to turn into a bomb and has vowed to use all means to prevent it from reaching that point. The U.S. has not said what its "red line" is, but has said it will not tolerate an Iran armed withnuclear weapons.

"The Iranians are using the round of talks to pave the way toward a nuclear bomb," said Yuval Steinitz, the Israeli minister for intelligence and strategic affairs, in a text message to reporters. "Israel has already warned that the Iranians are taking advantage of the rounds of talks in order to buy time to advance in uranium enrichment, step by step, toward a nuclear weapon."

Urging the international community to set a "short, clear and final timetable" for further talks, he said "the time has come for the world to show a more aggressive position and make it abundantly clear to the Iranians that their game of negotiations is coming to an end."

Any strike on Iran could provoke fierce retaliation directly from Iran and through its Middle East proxies in Syria, Lebanon and Palestine, raising the specter of a larger Middle East conflict and adding to the urgency of keeping both sides at the negotiating table.

At the talks in the Kazakh city of Almaty, the U.S., Russia, China, Britain, France and Germany were asking Tehran to greatly limit its production and stockpiling of uranium enriched to 20 percent, which is just a technical step away from weapons-grade uranium. That would keep Iran's supply below the amount needed for further processing into a weapon.

But the group views that only as a first step in a process. Iran is operating more than 10,000 centrifuges. While most are enriching below 20 percent, this material, too could be turned into weapons-grade uranium, although with greater effort than is the case for the 20-percent stockpile.

Tehran also is only a few years away from completing a reactor that will produce plutonium, another pathway to nuclear arms.

The U.N. Security Council has demanded a stop to both that effort and all enrichment in a series of resolutions since 2006. Iran denies any interest in atomic arms, insists its enrichment program serves only peaceful needs, says it has a right to enrich under the Nuclear Nonproliferation Treaty and describes U.N. Security Council demands as illegal.

The lack of progress at Almaty was a clear indication that Tehran wants greater rewards for any concessions that the six are ready to give. Among other incentives, they have offered to lift sanctions on Iran's gold transactions and petrochemical trade. But Iran demands much more substantial sanctions relief, including an end to international penalties crippling its oil trade and financial transactions

A senior U.S. official cited Iranian officials who described the six-power offer of limited sanctions relief in exchange for meeting their demands on 20-percent uranium as a "turning point" when the two sides met last month. The official said the U.S. administration was "disappointed that this rhetoric did not carry over into our negotiations."

The official demanded anonymity as a condition for participation in a post-meeting briefing for reporters.

Jalili in turn urged the six powers to demonstrate their "willingness and sincerity" by taking appropriate confidence-building steps in the future" — shorthand for Iran's demand to lift major sanctions and offer other concessions.

At the same time, he suggested some potential give on the Iranian side, suggesting discussion on some curbs of 20-percent enrichment "can be continued in the talks" if the six "move away from hostile treatment ... of the Iranian people."

With Iran previously describing the crushing sanctions on its oil exports and financial transactions as hostile acts, his comments suggested that Iran would consider compromise only if those penalties were lifted. That is far more than the relief being offered, with the six prepared to remove sanctions only on Tehran's gold transactions and petrochemical exports.

In demanding recognition of its right to enrich, Iran may hope to exploit some differences among the six, with Russia in recent months pushing for concessions on that point as a way to break negotiating deadlock.

Russian Deputy Foreign Minister Sergei Ryabkov, who led his country's delegation at Almaty, said after the talks that Moscow "considers that it's necessary to recognize all rights of Iran, including enrichment." In exchange, he said Iran must accept more international monitoring of its nuclear program.

A British Foreign Office statement said "a wide gap remains between the parties. Iran's current position falls far short of what is needed to achieve a diplomatic breakthrough."

Indirectly warning of further sanctions, the statement urged Tehran to "consider carefully whether it wants to continue on its current course, and face increasing pressure and isolation from the international community, or to enter into meaningful negotiations."

But Ryabkov described the meeting as "undoubtedly a step forward." Those remarks, and his comments on enrichment, both to Russian news agencies, suggested differences exist among the six, despite assertions by negotiators from Western nations of total unity at the negotiations.

___

Associated Press writers Mansur Mirovalev in Almaty, Daniel Estrin in Jerusalem, James Heinz in Moscow and Cassandra Vinograd in London contributed to this report.

WASHINGTON (AP) — Bringing their emotional advocacy to the national gun debate, families of those killed in the Connecticut school shooting are appearing with President Barack Obama and walking the halls of Congress to plead for stricter regulations.

They already have helped push through the nation's most restrictive firearms law, which Gov. Dannel P. Malloy, D-Conn., signed Thursday.

With no lobbying background and fueled by the power of their emotions, a group of Sandy Hook Elementary School families can take credit for helping shape the measure as it moved through the state Legislature.

Now they're trying to do the same in Washington, where gun legislation is facing tough resistance. Congress is returning from spring break, and Newtown, Conn., families plan to spend the coming week on Capitol Hill.

Their goal of their personal appeals is to speak to every senator who has yet to express support for the gun legislation, and to show how the Dec. 14 shooting has affected their lives.

"I'm not a constitutional scholar and I'm not a Second Amendment specialist," David Wheeler, who lost his 6-year-old son, Benjamin, said in a telephone interview.

"I don't know the ins and outs of gun policy but I know ...," his voice trailed off as a sob catches in his throat. "But I now know one of the things that no father should ever know. And in our system of representative government we have to use our voices."

The families of the 20 children and six staff members killed in the December shooting at Sandy Hookare a diverse group politically.

They include gun owners, and Democrats and Republicans. They don't always agree on gun policy.

One father — Mark Mattioli, who lost his 6-year-old son, James — attended a National Rifle Association news conference last week to endorse a proposal to train school staffers as armed security officers.

But relatives of nine victims have come together with a nonprofit group called Sandy Hook Promise to sign a letter sent Thursday to senators. It asks them to vote to expand background checks for gun purchases, strengthen laws against gun trafficking and ban ammunition magazines with more than 10 rounds.

Nicole Hockley wonders if her 6-year-old son, Dylan, might be alive if shooter Adam Lanza hadn't been able to carry 10 magazines that held 30 rounds each into the school that day.

Lanza was able to fire 154 shots during a four-minute rampage in the school. But he stopped shooting briefly in Dylan's classroom to reload, giving 11 children time to escape.

"They ran for their lives," Hockley said. "Dylan was not so fortunate. If there were lower capacity magazine clips, there's a chance Dylan would be here with me today."

She drives home the point on visits with lawmakers by handing out a photo card — the kind she might have made for a family holiday greeting — with three pictures of her son.

The largest photo shows him wearing a Superman T-shirt. He's caught in a wide grin that brightens his whole face. "Honor his life," the card says under the dates, 3/8/06-12/14/12. "Stand with us for change. Now is the time."

Bill Sherlach passes out a similar card with photos of his wife, Mary, a school psychologist who died as she rushed toward Lanza, trying to stop the shooter. Sherlach said he tells lawmakers about the bravery displayed by his wife and the other school staffers, and he asks, "Can you show the same courage in your vote today?"

As powerful as their personal pain comes across, it may not be enough to overcome Congress' strong tradition of protecting gun rights. The prospects for barring large-capacity magazines are difficult, and senators have yet to reach a deal to expand background checks.

The Sandy Hook group is not pushing for an assault weapons ban, even though a ban would prohibit the sale of the specific Bushmaster model that Lanza used to kill their loved ones.

The proposed ban is the most politically divisive of Obama's proposals, in Congress and among Sandy Hook families. Senate leaders say it doesn't have enough votes to pass, and most of the families don't support it, either, believing that magazines are more important to prevent a mass shooting. But it has some supporters among the families.

"I don't think as a realist that you can expect to get to the ultimate on your first foray on this," Sherlach said. "But we're not going away."

Sandy Hook Promise started in the days after the shooting. A group of neighbors came together in their living rooms and decided they wanted to take action to heal the community and aid victims' families.

They started by helping shovel their driveways and giving funds to those on hard economic times. The nonprofit's founding members worked their personal and professional connections to figure out how to support public policy, from mental health to gun safety, that could prevent another shooting.

Co-founder Tim Makris left his job at a venture capital firm to become the group's executive director. "This is not about just guns," Makris said. "The gun is the enabler, the cause is mental health."

But right now the issue before Congress is guns.

Sandy Hook families sat in the front row during a March 28 event at the White House, where Obama prodded Congress to pass his proposals.

"Less than 100 days ago that happened, and the entire country was shocked," Obama said. "And the entire country pledged we would do something about it and that this time would be different. Shame on us if we've forgotten. I haven't forgotten those kids."

Obama plans to meet with Newtown families Monday when he travels to Connecticut for a speech at the University of Hartford Sports Center, close to the Capitol where the governor signed sweeping new gun restrictions into law Thursday.

The state law requires background checks for all gun sales. It also expanded Connecticut's assault weapons ban, created a registry of weapons offenders and immediately prohibited the sale of magazines capable of holding more than 10 rounds of ammunition.

Connecticut's Democratic House speaker, Brendan Sharkey, said the Sandy Hook families pleaded with lawmakers in private meetings to outlaw existing high-capacity magazines, not just the sale of new ones. Sharkey grew emotional in an Associated Press interview as he described how he had to tell them he didn't have the votes.

"There's just no way to describe what it's like when a parent is telling you this gives some — hopefully, some — meaning to their loss of their child and you're telling them no," Sharkey said. "They actually apologized for the meeting and for the fact that they put so much pressure. I'm like are you kidding me? These are your children."

Sharkey said the families suggested a compromise in which owners of the previously purchased high-capacity magazines would have to register them with the state police. It passed.

Nicole Hockley stood over the governor's left shoulder as he signed the law. The former stay-at-home mom is now putting her marketing career background to work full time for Sandy Hook Promise.

She has met with Vice President Joe Biden, members of Congress and Connecticut lawmakers, although she says she much rather be waiting for Dylan to come home from school each day.

"This is incredibly new to me and certainly not anything I ever expected to be doing in my life," Hockley said.

___

Associated Press writers Susan Haigh and Michael Melia in Hartford, Conn., contributed to this report.

Follow Nedra Pickler on Twitter at https://twitter.com/nedrapickler