US President Barack Obama attends a news conference with Vietnam's President Tran Dai Quang at the Presidential Palace Compound in Hanoi, Vietnam, May 23, 2016. [Photo/Agencies]

HANOI - President of the United States Barack Obama on Monday announced the United States is lifting a decades-long arms embargo on Vietnam.

Obama made the announcement at a press conference co-chaired with Vietnamese President Tran Dai Quang in Vietnam's capital Hanoi during his ongoing visit to the country.

Obama also made it clear that the United States may sell military weapons to Vietnam under a case-by-case basis, when answering questions from media during the conference.

The Vietnamese president, for his part, said that "Vietnam welcomes US decision to completely lift arms embargo on Vietnam."

The US imposed arms embargo on Vietnam in 1984. Vietnam has been under the embargo despite the normalization of diplomatic ties in 1995.

In July 2013, former Vietnamese President Truong Tan Sang and Obama launched the Vietnam-US comprehensive partnership during Sang's visit to the United States.

In 2014, the US partially lifted the 30-year-old arms embargo against Vietnam, allowing transfer of maritime security-related defense articles to Vietnam.

Pham Quang Vinh, Vietnamese ambassador to the US said in an interview with Vietnam's state-run news agency VNA ahead of Obama's visit that the embargo is "the last barrier in bilateral ties."

Obama arrived at Noi Bai international airport in Hanoi late Sunday night, kicking off his first visit as US president.

His visit, made at the invitation of Vietnamese President Tran Dai Quang, is scheduled to last till Wednesday.