Hours after Egyptian President Hosni Mubarak announced Tuesday that he would not seek re-election, President Barack Obama said the U.S. ally must begin making major changes to his government immediately if he wants to preserve stability in his country.

“What is clear and what I indicated tonight to President Mubarak is my belief that an orderly transition must be meaningful, it must be peaceful and it must begin now,” Obama said in remarks from the White House.

Obama spoke to Mubarak shortly after the Egyptian leader announced that he will not run in September’s election after 30 years of rule. Tens of thousands of protesters have filled Cairo’s streets for more than a week with demands of more freedoms, fair elections and an end to government corruption.

During their 30-minute conversation, Mubarak acknowledged that “the status quo is not sustainable and that change must take place,” Obama said.

“Egypt has known many moments of transformation. … This is one of those moments. This is one of those times,” Obama said.

The United States will continue to be a partner and a friend to Egypt “as they manage the aftermath of these protests,” the president said, and he praised the “passion and dignity” of those in Egypt who have been demanding more freedoms from their government.

“To the people of Egypt, the young people, we hear your voices,” Obama said. “I have an unyielding belief that you will determine your own destiny.”