A dizzying day spent chasing Egypt’s twisting drama of revolt left the Obama Administration struggling to impact the crisis and even to divine exactly what was going on.

President Barack Obama reacted with a flash of anger, a warning against repression and a sharply-worded statement after his counterpart Hosni Mubarak refused to walk into retirement or exile on Thursday.

But though he stiffened his tone towards Cairo and embraced raging street protests as never before, Mr Obama was constrained by a dearth of options at Washington’s disposal.

After a defiant Mr Mubarak said he would cede some power but stay in office, Mr Obama said Egyptians needed to know if the transition was genuine – and strongly suggested it was not.

“The Egyptian government must put forward a credible, concrete and unequivocal path towards genuine democracy, and they have not yet seized that opportunity,” he said.

White House officials had at first Thursday declined to join rising euphoria buzzing on cable television amid reports and rumors that Mr Mubarak was set to go.

But President Obama, on a visit to Michigan, pulled a minor surprise, offering his strongest endorsement yet of Egypt’s protests, saying the world was watching “history unfold”.

“We want those young people and we want all Egyptians to know that America will continue to do everything that we can to support an orderly and genuine transition to democracy in Egypt,” he said.

Mr Obama’s remarks appeared a strong sign that the White House had reason to believe the 82-year-old strongman had decided he could hang on no longer.

The White House move may have also been motivated by a desire to clear up its public message amid scenes of confusion – after CIA chief Leon Panetta said during a congressional hearing it was likely Mr Mubarak would quit.

But the CIA quickly rowed back his comment, however, saying that he was responding to news reports and not citing any US intelligence – an embarrassment for a US spymaster.

Mr Obama’s first indication the drama was taking a lurch for the worse came as he and aides watched Mr Mubarak’s defiant speech to his countrymen on TV from Air Force One’s plush interior.

First, Washington had to figure out exactly what had just happened: Mr Mubarak’s speech left many observers confused as to the extent of his handover to Vice President Omar Suleiman.

Then it had to confront the possibility that fury in the Cairo crowds would translate to violence – Mr Mubarak’s declaration enraged hundreds of thousands of demonstrators who had occupied parts of central Cairo.

“It is imperative that the government not respond to the aspirations of their people with repression or brutality,” Mr Obama said.