Watch President Barack Obama's complete address.
Update 6:57 p.m. ET: President Barack Obama said in a brief address this evening that he has told Egyptian President Hosni Mubarak that an orderly and peaceful transition "must begin now."
The transition must include opposition parties, Obama insisted in remarks that came a few hours after Mubarak said he intended to stay in office through the end of his term in September.
Update 6:48 p.m. ET: The brief address is over. "There will be difficult days ahead," Obama says. "Questions about Egypt's future remain unanswered."
Update 6:45 p.m. ET: Obama confirms he spoke with Mubarak and says Mubarak "recognizes that the status quo" is unsustainable and says he told him an orderly transition "must begin now."
Update 6:45 p.m. ET: Obama praises the Egyptian military for not responding with violence.
Update 6:44 p.m. ET: President Obama is speaking now.
Update 6:19 p.m. ET: The White House pool now says timing on President Obama's speech is slipping. There is no ETA as yet.
President Barack Obama will make an address on Egypt at 6:20 p.m. ET, the White House says. We'll have live video and running coverage on this post. The address comes after Obama and Mubarak spoke today for about a half-hour, NBC News' Savannah Guthrie reports.