The US president has called on his Egyptian counterpart to take concrete steps towards political reform, and to refrain from using violence against thousands of protesters who have taken to the streets across Egypt.
"I want to be very clear in calling upon the Egyptian authorities to refrain from any violence against peaceful protesters," Barack Obama said in a statement shortly after speaking with Hosni Mubarak by telephone for 30 minutes on Saturday.
"The people of Egypt have rights that are universal. That includes the right to peaceful assembly and association. The right to free speech and the ability to determine their own destiny. These are human rights."
The statement came shortly after Mubarak went on national television to announce that he had dismissed Egypt's government.
Facing the prospect that a cornerstone Arab ally might collapse, the US administration has appealed for Egyptian authorities to halt the crackdown on swelling anti-government protests.
The US has warned citizens to avoid non-essential travel to Egypt and urged Americans in the country to stay put.
An administration official also said on Friday that the $1.5bn US assistance to the country would be reviewed.
The decision is a significant step as the US seeks to balance the desire to maintain stability in the region with a recognition of the unexpected scope and uncertain outcome of the protests aimed at toppling Mubarak's authoritarian government.
Protests across Egypt on Friday pose the most serious threat yet to the authoritarian Mubarak, a stalwart US ally in the Arab world considered a linchpin for American efforts to forge Middle East peace and tamp down extremism.
His support has been rewarded with billions of dollars in US aid each year over successive administrations.
"These protests underscore that there are deep grievances within Egyptian society, and the Egyptian government needs to understand that violence will not make these grievances go away," Clinton said.
She sidestepped a question on whether the US believed that Mubarak's regime was finished, but said that Washington wanted to work as a partner with both the country's people and government to help realize reform in a peaceful manner.
Clinton said that reform "is absolutely critical to the well-being of Egypt" and urged Mubarak and his government to "engage immediately" with opposition groups and others to make broad economic, political and social changes.
For years, the US has treaded a delicate line with Mubarak, supporting him to further America's Middle East agenda but trying to prod him on human rights and democracy.
