United States president-elect Barack Obama [Images] has said he is prepared for immediate American involvement in the Middle East peace process.

Obama, who takes over on January 20, said there could be delay in his election pledge to shut down Guantanamo Bay prison camps, but indicated reluctance to probe the charges that the previous administration eavesdropped and tapped the public at large.

Appearing in the ABC News programme 'This Week' just days ahead of his swearing-in, Obama pledged to take prompt action from day one on the Middle East peace process and warned that Iran's nuclear ambitions might trigger an arms race in the region.

"What I am doing right now is putting together the team so that on January 20, starting on day one, we have the best possible people who are going to be immediately engaged in the Middle East peace process as a whole, Obama said on ABC News programme 'This Week'.

"We are going to be engaging with all of the actors there. We will work to create a strategic approach that ensures that both Israelis and Palestinians can meet their aspirations," Obama said replying to a query on Gaza conflict.

Israel indicated on Sunday that it might stop its war on Hamas, amid clashes of an offensive that has killed nearly 900 people in the Gaza Strip.

On Iran's nuclear issue, Obama said, "I think that Iran is going to be one of our biggest challenges. We have a situation in which they are pursuing a nuclear weapon that could potentially trigger a nuclear arms race in the Middle East."

"And we are going to have to take a new approach. And I've outlined my belief that engagement is the place to start," Obama said.

On the time-frame for closing the Guantanamo Bay detention centres, Obama said, "I think it's going to take some time and our legal teams are working in consultation with our national security apparatus as we speak to help design exactly what we need to do."

"It is more difficult than I think a lot of people realise," the president-elect explained in what analysts say is an indication that he now plans to take a more measured approach than what he had advocated during his campaign.

The Guantanamo Bay prison holds some 250 "war on terror" suspects, mostly from Afghanistan.

Indicating reluctance to order a broad inquiry into the Bush administration's controversial programmes about eavesdropping and interrogations, Obama voiced his willingness to get specific cases investigated.

Obama said his team is still evaluating the whole issue of interrogations and detentions.

"Obviously, we are looking at past practices and I don't believe anyone is above the law," he told ABC.