Despite President Bush's optimism about progress toward gaining China's release of 24 U.S. military personnel, members of Congress are canceling a four-city tour of China scheduled for the Easter recess.

Initially, nine senators and 13 members of the House were scheduled to go. That changed after China refused to free the Americans detained after last weekend's collision of their Navy surveillance plane and a Chinese jet fighter. It was the third official China trip called off this week.

One by one, lawmakers peeled away, even though the Bush administration considered the trip a good idea.

"We had a briefing from the State Department, and actually they were encouraging us to go to maintain a sense of normalcy in our relationship with the People's Republic of China," Sen. Tim Johnson, D-S.D., said in an interview. "They want to view this as an accident and not an incident. Many members tend not to see it that way."

On Friday morning, Johnson was strongly leaning against going, barring a major move by China in the stalemate over the crew members.

Some remained interested.

"More than half dropped out yesterday, and it doesn't look good" for getting the military detainees' release, Sen. Lincoln Chafee, R-R.I., said in the morning. "But I'm still leaning toward going."

Then around noon, about a dozen of the House members and senators who were scheduled to go participated in a conference call that led to the cancellation of the trip, planned under auspices of the Aspen Institute.

"There were mixed views about the wisdom of going to China," Johnson said. "But by and large, the view was that it would not be helpful and that it would be a bad idea.

"There were those with contrary views, but there was also the understanding that it wouldn't look good for just a rump caucus to go to China," he said. "So having listened to it all, there was a general consensus even among people who wanted to go that the better idea would be to call this whole thing off and do it again, maybe next year."

Earlier in the week, Sen. Don Nickles, R-Okla., the Senate's second-ranked Republican, canceled a trade trip to China with Oklahoma business and government officials, and the chairman of the Senate Intelligence Committee, Sen. Richard Shelby, R-Ala., called off a committee trip.

Nickles said Friday he was unaware that the State Department supported congressional travel to China when he canceled his trip.

"I didn't cancel it at the request or the advice of the administration," he said. "I canceled it on my own, because I just didn't think it was appropriate to be doing a trade mission at the same time that we had 24 service men and women held against their will.

"Instead of being able to toast and talk trade and a more harmonious relationship, the tensions would be on what's going on, and I would be in an awkward position," Nickles said.

Johnson said he believed no congressional trips were heading to the China, although some still headed to Asia have removed China from their itineraries.