RIYADH, SAUDI ARABIA, DEC. 20 -- Pentagon officials, traveling here with Defense Secretary Richard B. Cheney, today disputed a top U.S. commander's assessment that American-led forces will not be ready for combat by Jan. 15, the United Nations deadline for Iraqi withdrawal from Kuwait.

A Defense Department statement, issued early this morning after all-night consultations with Washington, acknowledged that "some parts of the force become ready before others." But the statement noted that Air Force and Navy warplanes will be prepared for combat before ground troops have finished taking positions.

A senior official, speaking authoritatively for Cheney, twice called attention to the statement's single sentence on air power and cited "public speculation that {a U.S. attack} would start with an air component."

"This ain't no breather for Saddam Hussein," the official said.

Wednesday's remarks to reporters by Lt. Gen. Calvin A.H. Waller, the deputy commander of U.S. forces here, appeared to alarm officials traveling with Cheney and Gen. Colin L. Powell, chairman of the Joint Chiefs of Staff, and set off a scramble to decide on a response. Senior officials were so anxious to learn exactly what Waller had said about U.S. military preparedness here that a Navy commander was dispatched to awaken Voice of America correspondent Jane Berger at 3 a.m. for a copy of her cassette tape recording of the interview.

The Bush administration apparently feared that Waller's comments -- including a blunt assertion that Jan. 15 would find him "not ready to do the job" of attacking Iraq -- would dilute their "move it or lose it" message to Baghdad.

A competing interpretation of Waller's remarks -- that they were deliberately made to preserve an element of surprise in any attack -- was dismissed here by U.S. officials.

Lt. General John J. Yeosock, the Army's top commander in the Persian Gulf, used a previously scheduled interview with traveling reporters to emphasize that "I am ready today for whatever missions I am called upon to perform."

Yeosock was careful not to criticize Waller, a fellow three-star general who in some circumstances is senior in the chain of command, and there were few substantive differences between their statements. But where Waller had voiced the private cautions of many senior officers, Yeosock gave voice to the confidence that has characterized most public statements by those in authority.

Some officials attributed the flap to Waller's inexperience with reporters. They said he went too far in saying publicly what Cheney and Powell are hearing privately in far greater detail: that field commanders will be more confident of victory at lower cost if they can delay their attack until the arrival of all scheduled reinforcements.

Both Waller and Yeosock have made their careers in "heavy," or armored, units of the Army, and both generals are said to be particularly eager to complete the arrival of the Army's VII Corps from Germany.

It was a mark, perhaps, of the Pentagon's renewed sensitivity to public comment that Lt. Col. Mike Gallagher, a public affairs officer four grades Yeosock's junior, twice interrupted today's interview: once to "clarify" a remark, and once to tell Yeosock that he did not have to answer a question.

Yeosock in fact went to some lengths to leave the question unanswered: Had he ever met Saddam Hussein?

He first said he did not count Saddam among his friends, then said he had "met many people" in the Middle East, then said "I have met some people in passing," and finaly said, "I may have been in a crowd with him."

Yeosock, then a brigadier general, lived here from 1981 to 1983, helping modernize the Saudi National Guard. U.S. officers engaged in that time in a variety of cooperative activities with Iraq, and have not been eager to discuss them.