WASHINGTON (AP) — Talks are under way between the Obama administration and top Egyptian officials on the possible immediate resignation of President Hosni Mubarak and the formation of a military-backed caretaker government that could prepare the country for free and fair elections later this year, U.S. officials say.

With protests in Cairo and other Egyptian cities expected to grow in size and intensity Friday, 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 quickly. Creation of an interim government is just one of several possibilities under discussion, the officials said late Thursday.

The officials spoke on condition of anonymity to discuss the sensitive diplomatic talks, which are continuing.

The officials stressed that the United States isn't seeking to impose a solution on Egypt but said the administration had made a judgment that Mubarak has to go soon if there is to be a peaceful resolution to the crisis.

"The president has said that now is the time to begin a peaceful, orderly and meaningful transition, with credible, inclusive negotiations," a White House spokesman, Tommy Vietor, said 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."

White House and State Department officials 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.

An administration official said there is no single plan being discussed with the Egyptians. Rather, the administration is pursuing different ideas with Egyptian figures on how to proceed quickly with a process that includes a broad range of voices and leads to free and fair elections — in essence, different ways to accomplish those goals.

Among those options is a proposal for Mubarak to resign immediately — which the embattled president has refused to do — and for Mubarak 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 discussions come amid escalating violence between pro- and anti-Mubarak forces.

The chairman of the Joint Chiefs of Staff said Friday the U.S. hasn't raised its military readiness or alert status. Adm. Mike Mullen also said there shouldn't be any rush to terminate military assistance.

Mullen also reinforced Obama's call for a "peaceful, nonviolent transition" and said that decision ultimately must be made by the Egyptian people and their government.

As for U.S. assistance to Egypt, which has averaged about $1.3 billion a year, Mullen said Congress shouldn't move too hastily to cancel the program. Mullen said on ABC's "Good Morning America" he would "caution against doing anything until we know what's really going on."

The United States on Thursday severely criticized what it called systematic attacks on journalists in Egypt and said they appeared to be an attempt to shut out reporting of even bigger anti-government demonstrations to come.

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

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

Clinton pointed the finger at Mubarak's government without explicitly blaming the 82-year-old president for the violence. Egypt's government must hold accountable those responsible for the attacks and "must demonstrate its willingness to ensure journalists' ability to report on these events to the people of Egypt and to the world," she said.

Foreign photographers reported attacks by Mubarak supporters near Cairo's Tahrir Square, the scene of vicious battles between Mubarak supporters and protesters demanding he step down after nearly 30 years in power.

The Egyptian government has accused media outlets of being sympathetic to protesters who want Mubarak to quit now rather than complete his term as he has pledged.

White House spokesman Robert Gibbs offered a strong denunciation of reported "systematic targeting" of journalists. He said, "I think we need to be clear that the world is watching the actions that are taking place right now in Egypt."

On Capitol Hill, the Senate approved a non-binding resolution late Thursday urging Mubarak to hand over power to a caretaker government and begin a peaceful transition to a democratic society.

The administration's call for an immediate transition from three decades of authoritarian rule in Egypt has coincided with American hopes that reforms in Jordan and Yemen could stave off similar revolt.

All three countries have experienced instability since protesters in Tunisia chased their leader from power last month.

Separately Thursday, a senior intelligence official said Obama was warned of instability in Egypt "at the end of last year."

CIA official Stephanie O'Sullivan would provide no further detail during an open Senate confirmation hearing to be the deputy director of national intelligence.

The chairwoman of the Senate Intelligence Committee, Sen. Dianne Feinstein, D-Calif., told The Associated Press that the events "should not have come upon us with the surprise that they did."

She said the Internet's use in organizing demonstrations in Tunisia and Egypt should have provided "much more warning," and that her committee would look into how intelligence agencies performed.

"Was someone looking at what was going on the Internet?" she said.