Forty-four years after first setting foot in Vietnam as a young naval officer, US Secretary of State John Kerry has returned to the country seeking closer trade and security ties.
Kerry arrived in Ho Chi Minh City, formerly the capital of South Vietnam, on Saturday to strengthen diplomacy with an old US rival and raise human rights concerns.
"The US is prepared to assist Vietnam in its economic development and growth but at the same time believes that progress on human rights and rule of law is essential," a senior State Department official told reporters en route to Vietnam.
Kerry's visit comes as the US strives to reach a trade deal with 11 countries in the Asia-Pacific region, including Vietnam. A Trans-Pacific Partnership (TPP) trade deal is the centrepiece of US efforts to refocus attention on the fast-growing Asia-Pacific region.
But a letter by 47 members of the House of Representatives to Kerry last week expressed concern over growing arrests of bloggers and other activists in Vietnam.
A 2012 State Department report on human rights also cited restrictions on citizens' political rights and civil liberties in addition to corruption and arrests of religious groups as major problems in the country.
Kerry will also discuss ways the US can help increase Vietnam's security in case of escalating conflict with China over the disputed South China Sea.
The four-day trip will also include visits to the Mekong Delta and the nation's capital, Hanoi.
Kerry visited Vietnam 13 times as a senator, but this was his first trip to the country as top US diplomat.