'We're going to have to wait and see what's going on,' Obama said when asked for a comment while in Marquette, Michigan, where he was to speak on an unrelated domestic issue.
There were widespread reports by international media that Mubarak will step down Thursday night following more than two weeks of protests against his regime. If he resigns, it would mark an end to his 30 years of authoritarian rule.
The Obama administration has called on Mubarak, a close US ally in the region, to initiate an orderly transition of power and democratic and economic reforms in response to the mass protests.
'We're watching a very fluid situation,' said White House spokesman Robert Gibbs, travelling with Obama. Obama was monitoring the events on television and consulting with his foreign policy team.
'What were looking for and what the president spoke about many days ago remains our priority: an orderly transition to a free and fair election,' he added. 'What we're looking for remains unchanged.'
Gibbs said he will not 'prejudge what might happen later today' and would not comment on speculation about whether Mubarak will hand power to newly appointed Vice President Omar Suleiman or the military.
Meanwhile, the director of the CIA, Leon Panetta told a House of Representatives intelligence committee there was a 'strong likelihood' Mubarak will resign later Thursday.
'There is a strong likelihood that Mubarak may step down this evening, which would be significant in terms of where the, hopefully, orderly transition in Egypt takes place,' Panetta said.
Panetta added it was difficult to determine how the events in Egypt will unfold.
'When you have these events take place, it becomes very uncertain and very unpredictable,' he said.
The US State Department took the unusual step of delaying its regular daily briefing indefinitely following the reports of Mubarak's potential resignation.
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