President Barack Obama said Tuesday night he told Egyptian President Hosni Mubarak that change in Egypt "must be meaningful, it must be peaceful and it must begin now." Speaking at the White House following a telephone call with Mubarak, Obama said the Egyptian president -- who announced Tuesday he will not run for re-election -- recognizes "the status quo is not sustainable and that a change must take place." Obama made no mention of Mubarak's announcement that he had decided not to stand for reelection. Instead, Obama said he had told the Egyptian president that this was a "moment of transformation" in Egypt and that "the status quo is not sustainable." According to political sources, Obama's message was carefully calibrated to avoid publicly calling for Mubarak to stand down, while making clear he should stand aside. Administration officials say they are seeking a transitional government, with or without Mubarak as its titular head, formed by representative reform leaders and backed by the Egyptian army that will address legitimate grievances, restore stability and plan for a free election. "The key part of the statement was 'now,' " an administration official said. Obama's message to Mubarak had been conveyed earlier in the day by special envoy Frank Wisner during a meeting in Cairo. While Wisner said it would be useful if Mubarak made it clear that he had no plans to run in the scheduled September election, officials said, the bulk of the meeting was spent urging Mubarak to turn over control far sooner. Referring to massive anti-Mubarak demonstrations that have persisted for more than a week in Cairo and other Egyptian cities, Obama noted Egypt has undergone "many transformations" in its history. "The voices of the Egyptian people tell us that this is one of those moments," he said. "I indicated (to Mubarak) my belief that an orderly transition must be meaningful, it must be peaceful and it must begin now," Obama said. The U.S. president reiterated that the United States opposes violence and commended the Egyptian military "for the professionalism and patriotism that it has shown thus far in allowing peaceful protest while protecting the Egyptian people." He urged the military to "continue its efforts to help ensure that this time of change is peaceful." Obama repeated an assertion the U.S. government has made several times during the protests in Egypt, that freedom of assembly and speech and access to information are universal human rights. He said the Egypt's power transition must include "a broad spectrum of Egyptian voices and opposition parties, elections that are free and fair and a government grounded in democratic principles and responsive to aspirations of Egyptian people" but he acknowledged "there will be difficult days ahead." The 82-year-old Mubarak, whose regime has lasted nearly 30 years, said Tuesday he would remain in office until elections are held this fall.