WASHINGTON – President Bush will tell the nation Thursday evening that he plans to reduce the American troop presence in Iraq by as many as 30,000 by next summer but will condition those and further cuts on continued progress, The Associated Press has learned.

In a 15-minute address from the White House at 9 p.m. EDT, Bush will endorse the recommendations of his top general and top diplomat in Iraq, administration officials said.

The officials spoke on condition of anonymity because Bush’s speech is not yet final. Bush was rehearsing and polishing his remarks even as the U.S. commander in Iraq, Gen. David Petraeus, and U.S. Ambassador, Ryan Crocker, were presenting their arguments on Capitol Hill.

In the speech, the president will say he understands Americans’ deep concerns about U.S. involvement in Iraq and their desire to bring the troops home, they said. Bush will say that after hearing from Petraeus and Crocker he has decided on a way forward that will reduce the U.S. military presence but not abandon Iraq to chaos, according to the officials.

The address will stake out a conciliatory tone toward Congress. But while mirroring Petraeus’ strategy, Bush will place more conditions on reductions than his general did.