Updated

The Obama administration is in talks with top Egyptian officials about the possible immediate resignation of President Hosni Mubarak and the formation of an interim government that could prepare the country for free and fair elections later this year, U.S. officials said late Thursday.

Creation of a military-backed caretaker government in Egypt is one of several ideas being discussed as anti-Mubarak protests escalate in the streets of Cairo and other Egyptian cities, the officials said. Those protests are expected to grow in size and intensity on Friday and the administration fears they may erupt into more widespread violence unless the government takes tangible steps to address the protesters' main demand that Mubarak leave office.

A senior administration official suggested to Fox News that the proposal was one of several being discussed.

"It's simply wrong to report that there's a single U.S. plan that's being negotiated with the Egyptians," the official said.

The developments came after Mubarak said earlier Thursday in an interview with ABC News that he wants to leave office now but cannot for fear the country will sink deeper into chaos. He announced earlier this week his intention to end his three-decade rule, but only after elections in September.

Chaos already prevails in the streets of Cairo, where pro- and anti-government groups clashed for a second day Thursday in a central square, and further escalation is expected Friday.

Mubarak told ABC he is troubled by deadly violence in Cairo's Tahrir Square and that the government is not responsible for it. In the interview at the presidential palace, Mubarak blamed the outlawed Muslim Brotherhood for the violence.

White House and State Department spokesmen would not discuss details of the discussions U.S. officials are having with the Egyptians. Vice President Joe Biden spoke with Egyptian Vice President Omar Suleiman on Thursday, a day after a similar conversation between Suleiman and Secretary of State Hillary Rodham Clinton. Officials said neither Biden nor Clinton made a specific call for Mubarak to resign immediately but pressed for measures that would ease tensions on the streets and set the stage for democratic elections.

"The president has said that now is the time to begin a peaceful, orderly and meaningful transition, with credible, inclusive negotiations," said White House national security spokesman Tommy Vietor on Thursday night. "We have discussed with the Egyptians a variety of different ways to move that process forward, but all of those decisions must be made by the Egyptian people."

Among the options being discussed is a proposal for Mubarak to resign immediately -- which the embattled president has refused to do -- and for him to cede power to a transitional government run by Suleiman.

But the official rejected the notion that the White House was trying to impose that idea and said it was not at all clear it would happen. The official spoke on condition of anonymity to discuss internal deliberations.

The U.S. also is taking an increasingly direct public stance on the developing crisis. The Senate unanimously approved a resolution earlier Thursday urging Mubarak to hand over power to a caretaker government and begin a peaceful transition to a democratic society.

Responding to the days of rage in Egypt, Senate Foreign Relations Committee Chairman John Kerry  and Sen. John McCain joined forces in writing the bipartisan resolution and circulated it among lawmakers.

Secretary of State Hillary Clinton condemned "in the strongest terms" the pro-government mobs that beat, threatened and intimidated reporters in Cairo.

Attacks on peaceful demonstrators, human rights activists, foreigners and diplomats were "unacceptable under any circumstances," she said.

The new turn in U.S. involvement comes amid calls by protesters for Friday to be Mubarak's "day of departure" with a march on the presidential palace demanding his exit.

The protesters fought against Mubarak supporters in a second day of rock-throwing battles at a central Cairo square Thursday while new lawlessness spread around the city. Looting and arson erupted, and gangs of thugs supporting Mubarak attacked reporters, foreigners and rights workers while the army rounded up foreign journalists.

As bruised and bandaged protesters danced in victory after forcing back Mubarak loyalists attacking Tahrir Square, the government increasingly spread an image that foreigners were fueling the turmoil and supporting the unprecedented wave of demonstrations demanding the ouster of Mubarak, the 30-year authoritarian ruler.

"When there are demonstrations of this size, there will be foreigners who come and take advantage and they have an agenda to raise the energy of the protesters," Vice President Omar Suleiman said in an interview on state TV.

The White House said Vice President Joe Biden spoke with Suleiman by telephone on Thursday and condemned the recent violence. Biden urged restraint on all sides and restated the U.S. administration's support for universal rights, including the right to peaceful assembly, association and speech.

The White House statement said Biden stressed to Suleiman that the Egyptian government is responsible for ensuring that peaceful demonstrations do not lead to violence and intimidation and that journalists and human rights advocates should be allowed to conduct their work. He urged the immediate release of those who have been detained.

Among the many detained were correspondents for The New York Times, Washington Post and Al-Jazeera. Two Fox News journalists were briefly hospitalized after attacks. Human rights groups said many activists were taken away after a raid by the military police on a legal center in Cairo.

The Obama administration warned that the arrests and intimidation of reporters may be aimed at stopping the spread of the anti-government message ahead of a potentially critical protests Friday, when many Egyptians are expected to take to the streets after prayer services.

"It could well be that this is in anticipation of events tomorrow," State Department spokesman P.J. Crowley said. "We are bracing for a significant increase in the number of demonstrators on the streets and the real prospect of a confrontation."

Amid heightened U.S. concern about rising violence in Egypt, President Barack Obama began his remarks at Thursday's National Prayer Breakfast with pointed hopes for better days ahead: "We pray that the violence in Egypt will end and the rights and aspirations of the Egyptian people will be realized."

The Associated Press contributed to this report.