WASHINGTON — President Bush, declaring that a costly ground war may be unavoidable, said Tuesday he will rely solely on his military advisers in deciding any timetable for an assault on Saddam Hussein's Iraqi forces by U.S. and allied troops in Saudi Arabia.

Bush said he is dispatching Defense Secretary Dick Cheney and Gen. Colin L. Powell, chairman of the Joint Chiefs of Staff, to Saudi Arabia this week for a "firsthand status report" on the war and recommendations concerning a possible ground attack.

With Pentagon officials broadly agreeing that they will recommend a go-ahead for such an attack when the current air bombardment has destroyed 50% of Iraq's armored vehicles, some analysts now expect a ground war to begin within 10 or 20 days.

At that level of destruction, military analysts believe, Iraq's forces would be plunged into such chaos that they would no longer be able to function as an effective fighting force.

Brushing aside mounting congressional pressure to extend the air war to help minimize allied casualties, Bush said his decision will not be influenced by political opposition at home, anti-American sentiment in Arab countries or provocative actions by Iraq.

"Saddam Hussein will not set the timing for what comes next; we will do that," he told a press conference, raising his fist several times and speaking in blunt terms about U.S. military objectives and determination to prevail.

"And I will have to make that decision if we go to ground forces," he continued. "And I will do it upon serious consideration of the recommendations of our military," including Cheney, Powell and commanders in the field.

Bush also flatly ruled out any prospect that he might reinstate the draft. "I've heard no discussion from any of our people about the need to reinstate the draft," he said. "We have an all-volunteer Army that is totally capable of getting this job done."

In deciding the timetable for any ground assault, the President must worry about the potential for heavy casualties among allied forces if he moves too soon and about the possibility that the international anti-Iraq coalition will unravel if he delays too long.

Bush emphasized repeatedly, however, that in making his decision he will rely on advice from the military--Cheney, Powell and Gen. H. Norman Schwarzkopf, the U.S. commander in the Persian Gulf.