An Egyptian official complained that the U.S. was pressing for Mubarak's swift departure even as President Barack Obama publicly urges an orderly transition. "There is a clear contradiction between an orderly process of transition and the insistence that this process be rushed," said the official, who was speaking for his government but said the government would not allow his name to be associated with the statement.
"Now means now," White House spokesman Robert Gibbs said, and he declared anew that continued aid to Egypt would be influenced by the Egyptian government's response to the crisis.
While the U.S. has not directly called for Mubarak to resign - the protesters' chief demand - Gibbs was echoing Obama's public call one night earlier for an immediate and orderly transition to democracy in Egypt. Instead the images on TV were of a brutal clash between protesters and Mubarak supporters.
"If any of the violence is instigated by the government, it should stop immediately," Gibbs said, while declining to speculate whether the Egyptian government was in fact behind the violence. Protesters contended plainclothes police were among the pro-Mubarak groups.
The White House had attempted to nudge Mubarak to the exits, dispatching former U.S. Ambassador Frank Wisner as a special envoy to deliver the message to him. But by Wednesday, Wisner was on his way back to the United States.
A senior U.S. official, speaking on condition of anonymity due to the delicacy of the matter, suggested Wisner had been seeking specific pledges from Mubarak beyond just a promise not to stand for re-election. The official would not elaborate, but the administration has made no secret of the fact that it wants the state of emergency lifted and would prefer to see Mubarak's son, Gamal, not try to succeed his father. Mubarak mentioned neither in his address Tuesday night.
The White House said it had had no indication that such violence was in the offing when Obama and Mubarak had spoken frankly Tuesday night. The Egyptian president announced on television that he would not seek re-election in September, but protesters want him out now.
With Mubarak's grip on his country in doubt, Obama's team is evaluating scenarios of what may come next. But the conflict underscores the limits of the American president's power to shape the outcome.
For example, State Department spokesman P.J. Crowley acknowledged the hardline Muslim Brotherhood is "a fact of life in Egypt" and might play a role in the nation's transition. U.S. officials haven't met with members of the organization though they've spoken to other opposition groups, Crowley said.
He also said that Secretary of State Hillary Rodham Clinton had spoken with Egypt's new vice president to urge an investigation into attacks on protesters. She apparently was the first Cabinet-level official to reach out to Omar Suleiman, a longtime confidant of the U.S.
Clinton urged the government of Egypt to "hold accountable those who were responsible for violent acts", in a statement from the office of the State Department's spokesman released late Wednesday.
Clinton also "expressed hope that both the government and the opposition would seize the opportunity, starting immediately," created by Suleiman's call for "a broad dialogue with representatives of Egypt's opposition parties", the statement also said.
Obama has spelled out what Egypt's transition to free elections should look like, but he has refused to say whether Mubarak should be in charge all the while. Obama has spoken to Mubarak and telephoned fellow world leaders to try to bolster stability in the region, but he cannot stop violence in the streets of Cairo. To the degree Obama has spelled out consequences of inaction to Mubarak, the White House will not say much publicly.
Obama also is trying to find a balance between responding appropriately to events without being sucked up in hour-by-hour reaction. Gibbs said history was being made, and "this is not all going to be wrapped up in a matter of hours. It's going to take some time."
Sen. John McCain, R-Ariz., called for Mubarak to transfer power to a caretaker government immediately, saying the conditions in Egypt were deteriorating too quickly. McCain issued a statement calling for Mubarak to step down shortly after meeting privately with Obama in the Oval Office.
Later, McCain said he did not tell Obama that he would call for Mubarak to relinquish the presidency. "I did not want to connect it to our meeting," he said. "We did discuss the overall situation but I didn't argue for any position. The president makes his decisions. "
Thousands of supporters and opponents of Mubarak battled in Cairo's main square on Wednesday, throwing stones, bottles and firebombs as soldiers stood by without intervening. The fighting started when several thousand Mubarak supporters, including some riding horses and camels and wielding whips, attacked anti-government protesters.
The White House said Obama found the images deplorable.
The unrest in Egypt was sparked by an uprising in Tunisia and is reverberating throughout the region. King Abdullah of Jordan on Tuesday sacked his government and named a new prime minister, bowing to public pressure. The United States expressed hope Wednesday that pro-Western governments in Jordan and Yemen could stave off revolutions.
Gibbs said Obama had received no indication from Mubarak Tuesday night about what was going to unfold on Wednesday in Cairo.
Gibbs didn't directly answer when asked whether Obama viewed Mubarak as a dictator, saying the Egyptian president had a chance to show who he was. Mubarak has been an important ally to the U.S. during his 30-year reign, ensuring passage through the Suez Canal and maintaining peace with Israel. But for many Egyptian people, these have been years of corrosive poverty, repression and corruption.
Steve Clemons of the New America Foundation, one of several Middle East experts who met with Obama and his advisers on Monday, said the president and his team realize this is not the last quake in the region.
"There's a sense that the team in the White House has that they can't just be Egypt focused, that everything they say and do here has got to begin to become a frame for what sorts of principles we stand for," Clemons said. "And that just being for democracy, freedom and freedom of assembly is vapid, that there has to be a deeper commitment to some structural changes. I don't think anybody really knows what that means yet."
Gibbs said the U.S. expects that whatever government comes into power will respect the treaties entered into by previous Egyptian governments - a clear reference to Egypt's peace agreement with Israel, which has provided an important measure of stability for the region.
American officials are keen to promote an ordered transition that safeguards Egypt's status as a powerful American ally in the Middle East, instrumental in promoting Arab-Israeli peace, countering Iran's growing influence and fighting terrorism.
Across the Arabian peninsula in Yemen, which al-Qaida has turned into a main battleground in the war on terror, President Ali Abdullah Saleh pledged not to seek another term in an attempt to head off his country's version of the unrest that has spread through the Arab world since Tunisian protesters overthrew their president last month.
U.S. officials said they were pleased with Saleh's agreement to include opposition elements in a reform process after over three decades dominating the political landscape in his country. Saleh is seen as an increasingly important partner of the United States, allowing American drone strikes on al-Qaida targets and stepping up counterterrorism cooperation.
Administration officials are hopeful that Saleh's move toward reconciliation with Yemen's opposition can provide momentum for significant democratic reforms. The officials, speaking on condition of anonymity because of the sensitivity of the situation, said the U.S. would encourage all parties to engage in a national dialogue to help the impoverished, violence-wracked country in its transition.
The United States also was keeping a close watch on developments in Jordan, a similarly key ally and the only Arab country in addition to Egypt to have concluded a peace agreement with Israel.
Associated Press writers Steven R. Hurst, Bradley Klapper, Matthew Lee, Erica Werner, Julie Pace and Darlene Superville contributed to this story.