In the period since diplomatic ties were normalised in 1995, trade between them has risen consistently and rapidly, especially after a Bilateral Trade Agreement was signed in 2001.
Just two years after the BTA, the US became Vietnam's top export market and the status continues, according to Minister of Planning and Investment Bui Quang Vinh.
Vietnam has also become the biggest ASEAN member in terms of exports to the US, overtaking powerhouses Thailand and Malaysia.
In 1995 bilateral trade was worth US$450 million. It reached US$36 billion last year, with Vietnam's exports being worth US$25 billion.
The US is ranked seventh out of 101 countries and territories investing to Vietnam. It has invested US$11 billion in 735 projects, though the actual figure may be higher since many US companies like Intel, Coca Cola, Procter & Gamble, and Chevron invest in Vietnam through their subsidiaries in third countries.
US FDI has contributed to Vietnam's social and economic development, enhancing the effectiveness of domestic resources, Vinh said.
Peter Ryder, general director of Indochina Capital, was quoted by Vietnam Economics Times as saying that FDI flows from the US to Vietnam are set to soar, especially after the country becomes part of the Trans Pacific Partnership.
Since 1995 Vietnam enjoyed dramatic economic growth, and the impact of trade with and investment by the US was a catalyst, he said.
The US's development aid to Vietnam has increased every year since 1995, reaching US$120 million recently. The assistance focuses on the economy, education, health, including US$89 million for HIV/AIDS prevention programmes, combating climate change, and tackling the consequences of the war.
The US has also launched a US$72 million programme to clean Da Nang Airport of Agent Orange.
The TPP involving 10 other countries apart from Vietnam and the US is a great opportunity for further cementing economic ties between the two countries.
Of the 10 ASEAN economies, Vietnam is thought to be fourth or fifth most important for US companies, but the success of the TPP negotiations could change that, creating a new structure for trade and investment between them.
Exports are likely to rise in both directions while US companies will be easily able to invest in new areas in Vietnam.
There are a number of new industries that will grow much faster in Vietnam if the TPP is signed. For instance, the government is trying to encourage the manufacture of medical devices, and the trade deal would help attract investment in this area. The TPP will also promote investment in agricultural processing.