Mubarak, succumbing to an uprising in his country after nearly 30 years of authoritarian rule, has opted not to run for re-election in September. Obama called that a ``psychological break'' for Mubarak and then challenged him to reflect on his next move. He did that with a blunt reminder that world is watching him.

   ``The key question he should be asking himself is, `How do I leave a legacy behind in which Egypt is able to get through this transformative period?''' Obama said. ``And my hope is _ is that he will end up making the right decision.''

   Those comments came in a response to a reporter's question about Egypt, the first one Obama has agreed to answer since the crisis began 11 days earlier. In a brief appearance with Canadian Prime Minister Stephen Harper, Obama would not answer whether a credible transition toward free, fair elections in September can begin while Mubarak remains in power.

   Protesters are adamant that Mubarak must go now; they have campaigned for days, at times met with violence in images that have captured the world.

   The latest rally in Cairo on Friday drew roughly 100,000 protesters, and it went off largely peacefully to the enormous relief of U.S. officials.

   The Obama administration has been talking with top Egyptian officials on the formation of a military-backed caretaker government that could prepare the country for new elections, potentially with the 82-year-old Mubarak stepping down and newly appointed Vice President Omar Suleiman in charge for the interim. Suleiman has offered negotiations with all political forces, including the banned Muslim Brotherhood, over constitutional changes needed to ensure a free vote ahead of September elections.

   On that front, Obama said only: ``My understanding is that some discussions have begun.''

   Secretary of State Hillary Rodham Clinton spoke Friday to Egypt's long-serving foreign minister, Ahmed Aboul-Gheit, but the State Department did not give details of the talk.

   U.S. officials have been deeply skeptical about Mubarak's commitment to legitimate transition talks.

   The U.S. president also said in his broadest terms yet that Egypt, no matter what, will be a changed country based on the demonstrated will of its people.

   ``Going back to the old ways is not going to work,'' Obama said. ``Suppression's not going to work. Engaging in violence is not going to work. Attempting to shut down information is not going to work.''

   Harper showed solidarity.

   ``I don't think there is any doubt from anyone who is watching this situation that transition is occurring and will occur in Egypt,'' the Canadian leader said. ``The question is what kind of transition this will be and how it will lead. It is ultimately up to the Egyptian people to decide who will govern them.''

   With each day of unrest and little visible progress, the White House has been under deep pressure to prod a better outcome. But Obama has ensured in every public statement to balance his interests, underscoring Egypt's friendship and strategic importance to the United States, and declaring anew that ``it is not us who will determine that future'' for Egypt.

   Obama also said the United States has sent a strong, clear message that attacks on journalists, human rights activists and peaceful protesters are unacceptable. He did not directly blame Mubarak but said the Egyptian government is responsible for protecting its people.

   The chairman of the U.S. Joint Chiefs of Staff said Friday the United States has not raised its military readiness or alert status.

Adm. Mike Mullen also said there should not be any rush to terminate military aid to Egypt.

   In Congress, Rep. Gary Ackerman, a New York Democrat and member of the Foreign Affairs Committee, urged Obama to suspend aid to Egypt until a transition from Mubarak begins. ``I believe it essential to our national security interests that the world's largest Arab state know that America's commitment to democracy is real, and that we will not continue to underwrite a regime organizing violence against its people,'' Ackerman said.