Barack Obama will meet communist Vietnam's senior leaders on Monday, kicking off a landmark visit that caps two decades of post-war rapprochement, as both countries look to push trade and check Beijing's growing assertiveness in the South China Sea.
The visit to the dynamic and rapidly growing southeast Asian nation is Obama's first -- and the third by a sitting president since the end of hostilities in 1975.
In that time the two countries have experienced an astonishing turnaround in their relations from bitter foes physically and psychologically scarred by a decade of war to increasingly codependent regional allies.
Both nations have long pushed for closer trade ties, with the US hoping to tap into Vietnam's burgeoning middle-classes. Hanoi's leaders meanwhile are keen to continue delivering impressive growth to stave off the threat of opposition to their authoritarian rule.
But Washington and Hanoi also share increasingly common security goals, particularly as Beijing continues to flex its muscles in the disputed and strategic South China Sea where Vietnam also claims ownership of key islands and reefs.
The Obama administration has pitched this week's trip as an opportunity to push ties beyond the rapprochement period, with Vietnam now a vital plank in America's much vaunted pivot to the Asia-Pacific region.
"This visit is a significant upgrade in the relationship between the United States and Vietnam as partners on many issues," Ben Rhodes, Deputy National Security Advisor, told reporters ahead of the visit.
On Monday morning Obama will meet the country's president, its prime minister and the country's de facto leader Nguyen Phu Trong, the general secretary of the Communist Party.
Trong and Obama met last July, when he was given a prestigious Oval Office meeting.
A major talking point will be the lifting of a US arms embargo, a last vestige of the decade-long war between the two nations.
Advocates argue an embargo lift is vital to helping Vietnam improve coastal defences and bolster its outdated, largely Russian-origin military equipment to better counter Beijing.
- 'Look towards the future' -
But weighing against it are concerns about communist-ruled Vietnam's still dismal human rights record, an issue Obama is expected to touch on in a speech in Hanoi on Tuesday.
Increased trade ties will also feature prominently during the trip, with Obama keen to make the case for a trans-Pacific trade deal that faces an uncertain future.
On Tuesday afternoon Obama will fly to Ho Chi Minh City, the southern Vietnamese metropolis formerly known as Saigon which, in the 40 years since American troops hastily beat a retreat, has transformed itself into the country's thriving commercial heart.
There he will meet with tech entrepreneurs and hold one of his trademark town hall gatherings with young people.
In an overnight note, the State Department said both countries had announced a partnership to help tackle the fallout of climate change in Vietnam, a country particularly vulnerable to flooding and creeping salinisation.
The visit comes at a time when America has rarely, if ever, been so popular among ordinary Vietnamese.
A poll last year by the Pew Research Centre found 78 percent of Vietnamese have a favourable view of the US, the third highest in Asia after the Philippines and South Korea.
The approval rate was even higher among young people, a huge demographic in a nation where the median age is around 29.
Like most Vietnamese, 25-year-old Doan Quang Vinh from Hanoi was born long after the war.
"For me, the American war against Vietnam is a matter of the past, and though we must not forget the past, we should not dwell on it. We should look towards the future," he told AFP.
Thuy Tien, 19, likened Obama to communist Vietnam's founding father Ho Chi Minh.
"I've heard lots of stories, and I admire his achievements,” she said, giggling. "He's just like our Uncle Ho!"