WASHINGTON – President Bush opened the Oval Office yesterday to the highest-ranking official from communist Vietnam to visit since the end of the war that divided America and claimed the lives of more than 58,000 American troops.

Mr. Bush said he would visit Vietnam next year.

The president and Prime Minister Khai talked about the continuing search for American soldiers’ remains to close what Mr. Bush called a “sad chapter.” But they focused their attention on Vietnam’s desire to join the World Trade Organization as well as its human rights record, which some lawmakers say remains tainted.

“The Vietnamese economy is growing quite substantially,” said Mr. Bush, who announced plans to attend an Asia-Pacific economic summit next year in Hanoi. “We talked about our desire for Vietnam to join the WTO. We talked about security issues and a mutual desire to coordinate in the war on terror.”

The president also noted the Vietnam Religious Freedom Agreement, an accord signed in May that Mr. Bush said would make it easier for people to worship freely in Vietnam.

Senator Brownback, a Republican of Kansas, and 44 other members of Congress sent a letter to Mr. Bush urging him to keep pressuring Vietnam to improve its human-rights record and noting that last year, for the first time, the State Department designated Vietnam a “country of particular concern” for violating religious freedom.

Human Rights Watch says hundreds of dissidents have been jailed on criminal charges for advocating democratic reforms or using the Internet to disseminate proposals for human rights and religious freedom.

In the House, Rep. Chris Smith, a Republican of New Jersey, called Mr. Khai a “master of deception” and pledged to hold hearings in Congress between now and the summit in Hanoi to see if the agreement was being implemented. “It won’t take long to find out if this is a public-relations coup on the part of Khai or whether it’s sincere,” Mr. Smith said.

White House press secretary Scott Mc-Clellan said Mr. Bush discussed the importance of moving forward on improving human rights and expanding religious freedom. “Vietnam has taken some steps,” Mr. McClellan said. “We welcome those steps. There is more to do.”

As the two leaders met, several hundred protesters across from the White House demonstrated against repressive conditions in the communist nation. The noisy protesters chanted and carried signs that said “Stop Religious Repression” and “Vietnamese Communist Party Nazi Party.”

The chairman of the Vietnam Veterans Memorial Fund in Washington, D.C., John Wheeler, expressed dismay at the demonstration. “Vietnam is making real progress,” said Mr. Wheeler, who graduated from West Point and served in the war in 1969 and 1970.