As the U.S., Britain and Spain abandon efforts to win U.N. approval for a new resolution on Iraq, President Bush prepares to address the nation at 8 p.m. ET. White House spokesman Ari Fleischer says Bush will issue an ultimatum to Saddam Hussein, that the Iraqi leader leave the country or face war. And Secretary of State Powell says the "time for diplomacy has passed." Hear NPR's Vicky O'Hara and Michele Kelemen.