US President Barack Obama vowed Friday to keep Iran from acquiring nuclear weapons capability but urged hardliners in Congress to give talks between Iran and world powers a chance to succeed, dpa reported.
"There is no need for new sanctions legislation - not yet," he said in a year-end press conference at the White House.
The White House has said Obama would veto legislation, introduced by prominent senators from both parties, to institute sanctions if Iran violates the six-month interim agreement reached last month in Geneva, or if a final agreement is not reached.
He said the talks would determine whether it was "possible for Iran to get right with the international community" to build verifiable confidence that Tehran will not weaponize nuclear technology to threaten the United States or its allies in the region, including Israel.
"It is very important for us to test whether that's possible, not because it's guaranteed, but because the alternative is possibly us having to engage in some sort of conflict to resolve the problem, with all kinds of unintended consequences," Obama said.
He reiterated long-stanging US policy of "keeping all options on the table" with Iran.
"But I sure would rather do it diplomatically," he said. "And I would think that would be the preference of everybody up on Capitol Hill, because that sure is the preference of the American people."
The measure in Congress would put new restrictions on Iranian petroleum purchases and institute new penalties on the Iranian economy, including the engineering, mining and construction sectors.
Obama touted the interim agreement, which eases some international sanctions while Iran foregoes enrichment of uranium to a level of 20 per cent, as achieving some rollback of Iran's nuclear capabilities for the first time in almost decade.
The agreement forged between Iran and six major powers - the US, Britain, France, Russia, China and Germany - includes verification provisions and inspections. Many painful banking and economic measures remain in place during the interim agreement.
If violations occur or the process fails, the international community can easily "turn the dials back, strengthen sanctions even further. I'll work with members of Congress to put even more pressure on Iran," Obama said. "But there's no reason to do it right now."