President Bush said Tuesday that he accepted an invitation by the Vietnamese prime minister to to visit in 2006.

The trip would be the second by a U.S. president since the communist-led North Vietnam defeated the U.S.-backed South Vietnam three decades ago.

President Bill Clinton went to Hanoi, the Vietnamese capital, for a three-day visit in 2000. His was the first visit since 1969, when President Richard Nixon spent six hours rallying U.S. troops in the country.

In the meeting that marks a decade of normalized relations, Vietnamese Prime Minister Phan Van Khai (search) asked Bush to help his nation join the World Trade Organization (search) while Bush raised concerns about human rights abuses.

The 71-year-old Vietnamese leader met Bush in the Oval Office during a weeklong visit to the United States, where he is meeting with business leaders on both coasts. Khai is ringing the opening bell at the New York Stock Exchange later this week — evidence of Vietnam's economic gains over the years.

"The United States strongly supports Vietnam's integration into the world economic community and its bid to join the World Trade Organization," White House press secretary Scott McClellan said Monday. "They will also use this as an opportunity to work to address religious freedom and human rights concerns."

In the Oval Office, Khai acknowledged that differences remain between the two nations, but that his visit proved that Vietnam-U.S. relations had entered a new stage of development. "I'm fully confident that my visit to America this time will help uplift the relationship between our two countries to a new height.

Khai's talk with Bush is part of a weeklong visit to the United States where he is meeting with business leaders on both coasts. Khai is ringing the opening bell at the New York Stock Exchange later this week -- evidence of Vietnam's economic gains over the years.

"We have a population of 80 million people, which means a huge market for American businesses," Khai said.

After his discussions with Bush, Khai planned to meet with Defense Secretary Donald H. Rumsfeld. Military ties between the two countries have included periodic docking of U.S. warships in Vietnam and plans for U.S. military training of Vietnamese officers. Intelligence sharing and cooperation on counterterrorism activities also are part of the mix.

Also Tuesday, officials from the two countries will sign an agreement at the State Department to cooperate on adoptions.

In the 10 years since diplomatic ties were restored after the Vietnam War, the United States has become Vietnam's top trading partner. Last year, two-way trade was worth $6.4 billion.

After he arrived in the United States on Sunday, the Vietnamese leader stopped at Boeing Co.'s plant south of Seattle to oversee the purchase of four 787 airliners by Vietnam Airlines.

On Monday, Khai met with Microsoft Corp. Chairman Bill Gates (search) at the company's headquarters in Redmond, Wash. The two announced that they had signed two memoranda of understanding, to train and develop more Vietnamese information technology companies and to offer computer and software training to more than 50,000 teachers.

While Khai will want to talk about business, Bush is being pressured by human rights groups and some members of Congress to link any trade concessions with improvements in Vietnam's human rights record. "There are some steps that have been taken by Vietnam, but there are concerns that remain," McClellan said.

The U.S.-based Human Rights Watch (search) says it has documented cases of abuses by the communist government, including the arrests of dissidents for promoting democracy or human rights. In Seattle, Khai was greeted by demonstrators who shouted "Down with communists!" and called for an end to political and religious persecution.

During Sunday's demonstration, Nhien Le, a former officer in the South Vietnamese Air Force, said his fellow demonstrators hoped their presence would let Khai know that Vietnamese Americans want him to address human-rights abuses in Vietnam.

Bush and Khai also are expected to deepen joint efforts to achieve the fullest possible accounting for Americans who remain missing from the Vietnam War. Veterans groups and families of servicemen still missing in Indochina criticized the Republican-controlled Congress back in 1995 when President Clinton took steps to restoring relations between the once bitter enemies.

Khai's visit this week has not prompted any of that opposition, in part because Vietnam is cooperating in the search for U.S. service members. On Wednesday, Khai is to spend some time with Sen. John McCain, R-Ariz., a former Navy pilot who spent nearly six years in Vietnamese prisons after his plane was shot down during the Vietnam War.

After Washington, Khai is to travel to Massachusetts, where he will visit the presidents of Harvard University and the Massachusetts Institute of Technology.

The Associated Press contributed to this report.