Joe Biden arrives in Vietnam on Sunday to deepen cooperation between the two nations, in the face of China's growing ambitions in the region.
Biden — who is flying from the G20 summit in New Delhi — will meet the leader of Vietnam's ruling Communist Party, Nguyen Phu Trong, on Sunday, and is expected to sign off on a «comprehensive strategic partnership», Hanoi's highest level of diplomatic ties.
The underlying goal of the short visit will be much the same as Biden's time at the G20 gathering — to shore up support against China's increasing influence.
For Vietnam, the upgrading of diplomatic ties is significant.
It only has top-level ties with Russia, India, South Korea and China.
Although it will be careful to be seen as not taking sides between the United States and China, Vietnam shares American concerns about its neighbour's growing assertiveness in the contested South China Sea.
But just ahead of Biden's visit, the New York Times reported that Vietnam was secretly arranging to buy arms from Russia, in contravention of US sanctions.
The report cited a Vietnamese finance ministry document that laid out plans to finance arms purchases from the Kremlin through a joint oil and gas project in Siberia.
AFP has contacted the Vietnamese government for comment.
The United States and Vietnam — a key manufacturing hub — also have increasingly close trade ties, and Washington sees Hanoi as an important partner as it looks to source less from China after supply chain shocks rocked the global economy in recent years.
In Hanoi on Sunday, there will be a welcome ceremony, speeches by the two leaders and a press conference by the US president — who on Tuesday awarded the top US military honour to a helicopter pilot who rescued four