US President Barack Obama has said the resignation of Egyptian President Hosni Mubarak is the beginning of Egypt's transition to democracy, not the end.
In remarks at the White House, Mr Obama warned of "difficult days ahead".
And he called on the Egyptian military to end an oppressive emergency law, revise the constitution and begin preparing for free and fair elections.
Mr Mubarak has handed power to the military. Mr Obama said he had answered Egypt's "hunger for change".
"Many questions remain unanswered," he said. "But I am confident that the people of Egypt can find the answers, and do so peacefully, constructively, and in the spirit of unity that has defined these last few weeks.
"For Egyptians have made it clear that nothing less than genuine democracy will carry the day."
Later, giving his last press conference as White House spokesman, Robert Gibbs called on the next government of Egypt to uphold the country's 1979 peace treaty with Israel.
'Friend and partner'
In his remarks to reporters, Mr Obama praised the Egyptian military, which declined to respond to protests with violence, saying its members had served patriotically and responsibly.
In addition, Mr Obama called on the country's new military government to protect the rights of Egyptian citizens, rewrite the legal code to make the movement toward democracy "irreversible", and to lay out a clear path to fair and free elections.
He said that during the transition, all Egyptian voices should be represented at the negotiating table.
"The US will continue to be a friend and partner to Egypt," he said, pledging that the US would provide whatever assistance was necessary - and requested by Egypt - to aid the transition.
"A democratic Egypt can advance its role of responsible leadership not only in the region but around the world," he said.
Mr Obama compared the youthful Egyptian protest movement to the Germans who tore down the Berlin Wall, Gandhi leading India to independence, and the Indonesian popular protest movement that had succeeded in forcing President Suharto to resign.
"Egyptians have inspired us, and they've done so by putting the lie to the idea that justice is best gained through violence," he said.
"For in Egypt, it was the moral force of non-violence - not terrorism, not mindless killing - but non-violence, moral force, that bent the arc of history toward justice once more."
And he quoted American civil rights icon Martin Luther King: "There's something in the soul that cries out for freedom."
He went on: "Today belongs to the people of Egypt, and the American people are moved by these scenes in Cairo and across Egypt because of who we are as a people and the kind of world that we want our children to grow up in."