President Obama phoned former President George W. Bush on Tuesday morning aboard Air Force One, hours before he is scheduled to deliver a major address on the end of combat operations in Iraq.

White House spokesman Bill Burton told reporters that the conversation lasted a few minutes, but said the call was private and details will not be made public.

White House press secretary Robert Gibbs said Monday that the call would likely happen — Obama also spoke to Bush before his speech announcing his withdrawal timeline in February 2009.

Gibbs acknowledged Bush and Obama's divergent views on the war, but said the U.S. would remain involved with the country in the long term.

"I do think it is important to remember, as you said, this is a commitment that the president made, and a commitment that he intends — and will keep," Gibbs said at his daily press briefing.

Gibbs reiterated Obama would not have invaded Iraq in 2003, but refused to say whether affairs would be better or worse off if the U.S. had not invaded the country under Bush.