Obama urges senators to delay new sanctions on Iran

US President Barack Obama Tuesday appealed to senators to delay voting for tougher sanctions on Iran, as part of his administration's continuing efforts to buy negotiators more time and space to seal a deal on Iran's controversial nuclear programme.

The president, joined by his national security team including Secretary of State John Kerry and National Security Advisor Susan Rice, had a two-hour closed-door meeting at the White House with the Senate leadership and heads and ranking members of the committees on banking, foreign relations, armed services and intelligence, Xinhua reported.

"The president made it clear that achieving a peaceful resolution that prevents Iran from obtaining a nuclear weapon is profoundly in America's national security interest," White House spokesman Jay Carney said at a regular press briefing.

"He indicated that new sanctions should not be enacted during the current negotiations, but that they would be most effective as a robust response should Iran not accept the P5+1 proposal or should Iran fail to follow through on its commitments."

Both Vice President Joseph Biden and Secretary of State John Kerry went to Capitol Hill last week to lobby for delayed sanctions.

Iran is set to resume negotiations in Geneva, Switzerland, Wednesday with Britain, China, France, Russia, the US plus Germany, known as the P5+1, after intensive talks there Nov 7-9 failed to produce a deal.

Obama stressed to the senators that without the initial step, Iran will continue to advance its nuclear programme by increasing its enrichment capacity, growing its stockpile of enriched uranium, installing advanced centrifuges and making progress on the plutonium track at the Arak reactor, according to Carney.

"With this current P5+1 proposal, we have the opportunity to halt the progress of the Iranian program, roll it back in key respects, while testing whether a comprehensive resolution can be achieved," Carney said.

Obama also told the senators the suggested sanctions relief will be "limited, temporary and reversible", dismissing reports about $40 to 50 billion in reduced sanctions for Iran as "inaccurate".