The Middle East crisis was likely to have been on the agenda at the White House meeting [AFP]

George Bush, the US president, and his successor, Barack Obama, have joined all the living former US presidents for a meeting at the White House.

Bush and Obama were joined by former presidents Jimmy Carter, Bill Clinton and George Bush for the lunch meeting on Wednesday.

Obama and the current president met privately before the meeting and were expected to discuss the struggling US economy and the crisis in the Middle East.

Earlier on Wednesday, Obama, who takes office on January 20, repeated that he was deeply concerned about the situation in Gaza but said it would be imprudent to send signals that his incoming administration is running foreign policy.

"I am doing everything that we have to do to make sure that the day that I take office we are prepared to engage immediately in trying to deal with the situation there," he said at a news conference.

"Not only the short-term situation but building a process whereby we can achieve a more lasting peace in the region."

Obama has refused to make any lengthy comments on the violence in Gaza, where more than 700 Palestinians have been killed in the 12-day Israeli offensive, which Israel says is to suppress rocket fire against its citizens from Gaza.

This has led to accusations both of siding with Israel with his silence or of failing to speak enough clearly in favour of the offensive in Gaza.

Presidential relations

At the presidents' meeting, Bush said he hoped Obama would succeed.

"All of us who have served in this office understand that the office itself transcends the individual and we wish you all the very best, and so does the country," Bush said to his successor.

"To the extent we can, we look forward to sharing our experiences with you.

"One message that I have and I think we all share is that we want you to succeed. Whether we're Democrat or Republican, we care deeply about this country," Bush continued.

Obama called the meeting extraordinary and thanked the current president for hosting it.

"All the gentlemen here understand both the pressures and possibilities of this office, and for me to have the opportunity to get advice, good counsel and fellowship with these individuals is extraordinary," he said.

Though they have much in common, relations between the presidents have at times been strained.

Carter has criticised Bush's presidency as "the worst in history" with regard to international relations and Clinton, who has a warm relationship with the elder Bush, criticised the current president and Obama sharply during his wife Hillary Clinton's presidential campaign last year.