US President Barack Obama warned that imposing new sanctions on Iran over its nuclear program will guarantee the failure of diplomacy.

US President Barack Obama warned that imposing new sanctions on Iran over its nuclear program will guarantee the failure of diplomacy.

Several U.S. Senators have been pushing to pass new sanctions on Iran as talks between the Islamic Republic and six world powers over its nuclear program drag on.

Any new sanctions on Iran passed by this Congress before the talks are completed "will all but guarantee that diplomacy fails," Obama said, promising to veto any such move.

"Our diplomacy is at work with respect to Iran, where, for the first time in a decade, we've halted the progress of its nuclear program and reduced its stockpile of nuclear material. Between now and this spring, we have a chance to negotiate a comprehensive agreement that prevents a nuclear-armed Iran; secures America and our allies – including Israel; while avoiding yet another Middle East conflict."

Last week the chairman of the Senate Foreign Relations Committee said Republican and Democratic US lawmakers will press ahead with a plan for more sanctions on Iran, despite White House warnings that they risked derailing nuclear talks.

"There are no guarantees that negotiations will succeed, and I keep all options on the table to prevent a nuclear Iran," said Obama -but "the American people expect us to only go to war as a last resort, and I intend to stay true to that wisdom."