Obama has lunch with former presidents

US President-elect Barack Obama has lunched at the White House on Wednesday with the current chief executive and three former presidents.

It was a symbolic show of support that Obama said provided "advice, good counsel and fellowship".

Before the rare meeting - the first such in the executive mansion since 1981 - Obama told Americans that reforming massive government entitlement programs would be "a central part" of his effort to control federal spending, even as he pushes Congress to appropriate hundreds of billions of dollars to jolt the crumbling US economy.

At Wednesday's gathering less than two weeks before Obama's inauguration, the president-elect stood for photos flanked by former President George HW. Bush on one side and his son, President George W Bush, on the other. Former Presidents Bill Clinton and Jimmy Carter, both smiling broadly, stood with them.

"I just want to thank the president for hosting us," Obama said.

"All the gentlemen here understand both the pressures and possibilities of this office," said Obama, who takes office on January 20.

"For me to have the opportunity to get advice, good counsel and fellowship with these individuals is extraordinary."

During the brief photo opportunity, the current president wished Obama well before all five men headed to a private lunch that lasted about 90 minutes.

"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 said.

"All of us who have served in this office understand that the office itself transcends the individual."

Bush and Obama also met privately for roughly 30 minutes in the Oval Office before the lunch.

Details of the one-on-one meeting, coming just 13 days before Obama's inauguration, were not revealed although they were expected to focus on grim current events - the war in the Gaza Strip and the crippled US economy.

Describing the gathering in only broad terms, Obama press secretary Robert Gibbs said: "The president and the former presidents had helpful advice on managing the office, as well as thoughts on the critical issues facing the country right now. The president-elect is anxious to stay in touch with all of them in the coming years."

While Obama pledged to take a knife to unnecessary government spending and to reform entitlements, he provided few details at the news conference where he named Nancy Killefer to the newly created position as chief performance officer. She is assigned the tasks of eliminating government waste and improving efficiency.

The promise to cut unnecessary government spending, coincided with a Congressional Budget Office estimate that Obama would inherit a $US1.2 trillion ($A1.7 trillion) federal deficit for fiscal 2009.

"We expect that discussion around entitlements will be a part, a central part of those plans," Obama said.

"And I would expect that by February, in line with the announcement of at least a rough budget outline, we will have more to say about how we're going to approach entitlement spending."

For the first time, Obama gave a ballpark price tag for his massive economic plan designed to put a floor under the country's deepening recession. Aides have said it could cost as much as $US775 billion over two years. Outside economists have suggested as much as $US1.2 trillion would be needed.

"We expect that it will be on the high end of our estimates but will not be as high as some economists have recommended because of the constraint and concerns we have about the existing deficit," Obama said.

On Thursday, he plans to give a speech on the economy at George Mason University in Virginia where he will lay out his reasons for pressing Congress to quickly approve his still-evolving economic plan.

Meanwhile, politicians have been distracted by an ugly bit of political theatre that unfolded in Congress on Tuesday when the Senate barred Roland Burris from taking Obama's vacated Illinois Senate seat. Burris was appointed by the state's embattled governor, Rod Blagojevich, who stands accused of trying to sell the position to the highest bidder.

On Wednesday, Burris met with Senate Majority Leader Harry Reid as the Senate Democrats looked for a way to defuse the stand-off and set forth the legal steps under which they would welcome him into the Senate.

Senate Majority Leader Harry Reid said the Senate is awaiting a court ruling in a case that tests whether the Illinois secretary of state is required to sign Burris' certification.

Burris, who would be the Senate's only black member, said on Wednesday that he expects "very shortly" to represent the state of Illinois in the US Senate.

Also on Wednesday, Senator Dianne Feinstein of California, the incoming chair of the Senate Intelligence Committee, said she intends to support President-elect Barack Obama's choice for CIA chief, Leon Panetta.

Feinstein had earlier expressed reservations about the choice of Panetta, a former White House chief of staff without a formal background in the intelligence community.

Obama had not consulted with Feinstein before making the choice and subsequently apologised to her for the lapse.