WASHINGTON, Nov 26: The Obama administration is urging Congress to hold off for another six months their plan to introduce new sanctions against Iran, US of ficials said on Tuesday.

As his aides reached out to senior congressional leaders for delaying the sanctions, President Barack Obama told his nation that now was the time to pursue diplomacy over conflict.

`Huge challenges remain.

But we cannot close the door on diplomacy, and we cannot rule out peaceful solutions to the world`s problems,` Mr Obama said in a speech in San Francisco.

The US and five other world powers signed a deal with Iran this weekend, which seeks to cap Tehran`s nuclear capabilities in return for relaxation of US-led sanctions, which had crippled the Iranian economy.

`Now that`s the right thing to do. That`s good for the United States. It`s good for our allies. It`s good for Israel, said Mr Obama while responding to criticism that his deal with Iran had jeopardised the security of America`s closest ally in the region, Israel.

On Tuesday, the US media reported that Mr Obama had sent his senior aides to congressional leaders with a message that bringing new sanctions at this stage would hurt the deal concluded in Geneva.

The aides are believed tohave told the lawmakers to delay the sanctions for six months so that they could hammer out a long-term agreement with Iran for ending its pursuit of nuclear weapons.

The present deal is an interim arrangement and both sides are required to conclude a permanent solution by late 2014.

In a bid to allay lawmakers` fear that the deal would allow Iran to secretly pursue its nuclear ambitions, Mr Obama said he had gone into negotiations with Iran `clear-eyed`.

Mr Obama recalled that when he came into office, `there was a lot of bluster about Iran` but no real plan to curb its nuclear programme.

`And so, with the help of members of Congress... weconstructed the toughest set of sanctions ever` and also brought in those `who were very reluctant to apply sanctions Russia and China`, he added.

And as a consequence of the agreement concluded in Geneva, the world witnessed the first halt in the Iranian nuclear programme in a decade, the reduction to zero of the 20 per cent enriched uranium that was the biggest threat to immediate breakout capacity, Mr Obama said.

The US president said he preferred diplomacy to war because he spent a lot of time with young Americans wounded in the war. `I`m going to do every single thing that I can to try to resolve these issues without resorting to military conflict,` he added.