U.S. National Security Adviser General James Jones told participants at the J Street conference on Tuesday that the Obama administration believes "without equivocation" that "Israeli security and peace are inseparable."

Addressing delegates to the left-leaning pro-Israel group's conference in Washington, D.C., James declared that the Obama administration was steadfast in its commitment to Israel and was determined to help bring about an end to the conflict in the Middle East.

"Time is not necessarily on our side - the imperative for peace is now," he said. "America's commitment to Israel is not just a slogan and not something we signed on easily."

"This commitment for Israel and peace is as strong as ever in the face of the many challenges in the region," Jones added. "If I could advise the President to solve one problem among the many problems - this would be it. This is the epicenter, where we should focus our efforts... Our unshakeable bound with Israel is to ensure that Israel is treated fairly."

Jones told the delegates that while some of the U.S.' goals regarding the Middle East were moving along, there was still much work to be done. Primarily, he said, the sides must agree to resuming peace negotiations without preconditions.

"We made some progress towards the goal we set but we must do much, much more," he said. "It's time to re-launch negotiations without preconditions.

"We cannot forget people of Gaza and humanitarian situation there and the people of Southern Israel," Jones added. The task ahead will not be easy, there will be false starts and setbacks, but we'll get there."

Jones lauded J Street for a successful first national conference and said the administration was intent on returning to future conferences.

"I'd like to congratulate you on this impressive conference and I'm honored to represent President [Barack] Obama and make sure that we'll be represented in all future conferences," Jones said.

Turning to Iran, Jones warned that the United States would be ready to respond if Iran fails to take tangible steps soon to meet its commitments over its nuclear program.

""Nothing is off the table," Jones said, referring to Washington's options in dealing with Iran if it continues defying international demands.

He spoke after Iran's state media said Tehran wanted major amendments in the framework of a UN nuclear fuel deal that it broadly accepts. The diplomatic snag threatened to unravel the plan and expose Tehran to the threat of harsher sanctions.

"Iran now needs to follow through on its commitments," Jones told the J Street delegates.

The European Union's foreign policy chief said earlier on Tuesday there was no need to rework the UN draft, and he and France's foreign minister suggested Tehran would rekindle demands for tougher sanctions if it tried to undo the plan.

Jones said Iran's agreement to export low-enriched uranium to other countries would be a good first step toward reducing Iran's ability to build a nuclear weapon in the short term.

"If implemented, this arrangement would set back the clock on Iran's breakout capability as it would reduce Iran's stockpile far below the amount needed in order to produce a weapon, and it would take time to reconstitute the amount needed for a breakout," he said.

Jones said the administration had consulted Israel and other U.S. allies in the Middle East and Europe plus Russia and China and the consensus was "moving toward our direction" over Iran.

J Street kicked off its first national conference on Sunday with more than 1,500 guests at the Grand Hyatt Hotel in Washington, D.C. Despite controversy and tension surrounding the convention, organizers said the attendance exceeded expectations.

Numerous peace activists, politicians, diplomats, lobbyists, male and female rabbis, political advisers, artists, students and journalists filled the halls. Participants who spilled out from over-crowded panel rooms sat in a circle on the lobby carpet, heatedly discussing the state of left-wing activists in Israel and the United States, religion and the new media.

"We couldn't be more thrilled," said J Street executive director Jeremy Ben-Ami. "The numbers of participants far exceeded our expectations - 148 congressmen supported the event, 250 students and reporters from 17 countries came. This is truly the birth of a movement. It demonstrates the vacuum and the desire to promote peace now, when it's more urgent than ever... Our vision for peace is very clear - two states based on '67."

"Violence might break out, there are extremists on both sides," he continued. "But we can't allow the extremists to prevent a better future for both sides."

A reporter asked Ben-Ami how J Street could be pro-Israel when Israeli ambassador to the United States Michael Oren had boycotted the event.

"The Israeli ambassador is making a serious mistake. This is part of the Jewish community and to refuse to engage with us is a serious mistake, as it is to refuse to engage with those seeking to promote peace. I wish he were here even to express his disagreement. We do love Israel, we do support Israel. [But] we have questions regarding its policy," Ben-Ami said.