The war, which ended with the scrambled withdrawal of US forces in 1975, led to the deaths of more than 1.5 million Vietnamese and 58,000 Americans.
President Bill Clinton is the first US head of state to visit Vietnam since the end of the war there 25 years ago.
His four-day visit, which starts later on Thursday, is also his last scheduled foreign trip as US president.
The war, which ended with the scrambled withdrawal of US forces in 1975, led to the deaths of more than 1.5 million Vietnamese and 58,000 Americans.
Under the Clinton administration, Washington's relations with Hanoi have been transformed.
Now, his officials say, he intends to further the process of reconciliation and look ahead to Vietnam's future.
"In our national memory Vietnam was a war," the president said at a Veteran's Day ceremony shortly before the visit. "But Vietnam is also a country."
US anger
When President Clinton entered office in 1993, the United States had an economic embargo on Vietnam. He not only lifted the embargo but also restored diplomatic relations and, earlier this year, the two countries singed a bilateral trade agreement.
But Mr Clinton's visit has angered some veterans' organisations in the US, and those who lost family members in the war.
Internet chat-rooms devoted to Vietnam issues are filled with messages from veterans and others who want to see the message of reconciliation carried by somebody other than a man who went to such great lengths to avoid being drafted to Vietnam.
The Vietnamese are also well aware that Mr Clinton avoided fighting in Vietnam.
"We welcome President Clinton because he was himself against the war," said Lieutenant General Khai Hung Nguyen.
The general added that while the US was at fault for what happened in the war, he did not expect an apology.
"It is better to make up for what happened by actions," he said.
But some members of the older generation, like 100-year-old Tran Thi Mit, who lives on the site of a former battlefield, are opposed to the president's visit.
"I hate the Americans," she said. "They came here and killed my children."
Six of Tran Thi Mit's children were killed in the war, as were her husband and one daughter-in-law.
Missing persons
And despite the bright prospects between the two countries, both governments know they cannot avoid the past.
Thousands of tonnes of mines and unexploded ordinance remain in Vietnam's soil.
Surveys have also revealed the existence of high concentrations of dioxins left behind by Agent Orange - a defoliant which the US military sprayed on some 14% of Vietnam's land in an attempt to deny their Communist enemies food and cover.
Nearly 2,000 US servicemen and civilian men and women are still unaccounted for from the war and are designated Missing In Action (MIAs).
Mr Clinton has said accounting for these people and repatriating their remains is the administration's highest priority in its dealings with the Vietnamese Government.
Other discussions will focus on business and economic ties and human rights, particularly what the US regards as the mistreatment of religious groups and political dissidents in Vietnam.