WASHINGTON  - US President Barack Obama urged Iran on Sunday to seek a diplomatic solution to the nuclear stand-off, reaffirming his backing for key ally Israel and saying there was “too much loose talk of war.” Addressing a pro-Israeli lobby group in Washington alongside Israeli President Shimon Peres, Obama said international sanctions were working and cautioned against saber-rattling as Iran moves closer to a nuclear weapon. Obama also reaffirmed his strong backing for Israel and warned Iran’s leaders that he would not hesitate to use force, if required, to stop it developing a nuclear weapon. “Iran’s leaders should know that I do not have a policy of containment; I have a policy to prevent Iran from obtaining a nuclear weapon. And as I’ve made clear time and again during the course of my presidency, I will not hesitate to use force when it is necessary to defend the United States and its interests.”

“Because of our efforts, Iran is under greater pressure than ever before,” he told thousands of delegates at the American-Israel Public Affairs Committee (AIPAC) forum.

“Iran is isolated, its leadership divided and under pressure. And the Arab Spring has only increased these trends, as the hypocrisy of the Iranian regime is exposed, and its ally — the Assad regime (in Syria) — is crumbling.”

“I firmly believe that an opportunity remains for diplomacy — backed by pressure - to succeed,” Obama said.

“Already, there is too much loose talk of war. Over the last few weeks, such talk has only benefited the Iranian government, by driving up the price of oil, which they depend upon to fund their nuclear program.”

US intelligence is said to believe that Iran does not currently intend to produce nuclear weapons, though it may be seeking the capacity to do so, and Washington has emphasized the importance of deterrent sanctions and diplomacy.

But Israel is reportedly eager to move more quickly and decisively against Iran’s nuclear activities, using a military strike to prevent it from obtaining even the capacity to take a decision to produce nuclear weapons.

“For the sake of Israel’s security, America’s security, and the peace and security of the world, now is not the time for bluster; now is the time to let our increased pressure sink in, and to sustain the broad international coalition that we have built.”

Iran insists its nuclear program is for civilian energy purposes only.

Earlier, Israeli President Shimon Peres said in Washington Sunday that Israel “shall prevail” if forced to fight Iran, “an evil, cruel and morally corrupt regime” bent on controlling the Middle East..

His speech to a powerful pro-Israel lobby charged up the atmosphere for talks Monday between US President Barack Obama and Israeli Prime Minister Benjamin Netanyahu, who will tackle the perceived nuclear threat from Iran.

“Iran is an evil, cruel, morally corrupt regime. It is based on destruction, and is an affront to human dignity,” Peres told thousands of delegates at the American Israel Public Affairs Committee (AIPAC) forum.

“Iran is the centre, the sponsor, the financer of world terror. Iran is a danger to the entire world,” he said in an address that was to be followed by minutes later by a speech from Obama.

“It threatens Berlin as well as Madrid, Delhi as well as Bangkok. Not just Israel,” the veteran Israeli political leader said.