US President Barack Obama is in the midst of a three-day historic visit to Vietnam, and has undergone a series of meetings to discuss the US's relationship with the South Asian country.

Obama is the third US President to visit the south-east Asian nation since diplomatic relations were restored in 1995 and has made a strategic 'rebalance' towards Asia, a centrepiece for his foreign policy. Obama's visit comes 41 years after the end Vietnam War. The United States tried to prevent South Vietnam from becoming a communist country. The attempts failed, and in 1975 the entire country was under a communist rule.

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US President Barack Obama delivers a speech at the National Convention Center in Hanoi, VietnamCarlos Barria/ Reuters

Yet ties between the US and its former enemy are on the mend. On 24 May the US President signed an agreement allowing the US Peace Corps to work in the country for the first time, following over a decade of negotiations between the two countries.

According to Peace Corps Director Carrie Hessler-Radele, who signed the agreement with Vietnam's ambassador to the US, Pham Quang Vinh, the program is expected to begin over the next two years. It will allow Peace Corps volunteers to teach English in Vietnam's two largest cities Hanoi and Ho Chi Minh City.

"For 20 years now we have had what we call a normal relationship," US Secretary of State John Kerry, who served as a young US naval officer in the Vietnam War in 1968 and was present for the signing.

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A woman holding onto a photo of US President Barack Obama while cheering in Hanoi, near Vietnam's presidential palace as he begins his three-day visitLinh Pham/ Getty Images
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US President Barack Obama and his Vietnamese counterpart Tran Dai Quang listen to their countries' anthems during a welcoming ceremony held at the presidential palace in HanoiHoang Dinh Nam/ AFP
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US President Barack Obama walks with his Vietnamese counterpart Tran Dai Quang as they review a guard of honour during a welcoming ceremony at the Presidential Palace in HanoiKham
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A child dressed as Captain America waves at Obama's motorcade as the US President arrives in Ho Chi Minh CityCarlos Barria/Reuters
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US President Barack Obama delivers remarks at the National Convention Center in HanoiKham
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Children look at the motorcade transporting US President Barack Obama before an arrival ceremony at the presidential palace in HanoiCarlos Barria/ Reuters
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Local residents hold a sign welcoming US President Barack Obama as he arrives at Ho Chi Minh CityCarlos Barria/ Reuters

The signing comes after an announcement made on 23 May that Washington will lift an embargo on sales of lethal arms to Vietnam, underlining warming relations between the former enemies. However, the sales of arms will be made on a case-by-case basis, depending on Vietnam's human rights commitments.

The US President is urging Vietnam to respect freedom of speech, asking that the country demonstrates that these rights are written into the country's constitution. Obamas' concerns with the country's lack of political rights were highlighted after critics of the communist-run government and Vietnam activists were prevented from meeting him in Hanoi.

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A model of an airplane at the Vietnam People's Air Force Museum in HanoiLinh Pham/ Getty Images
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Posters of US President Barack Obama in front of a barber shop on May 23, 2016 in Hanoi,Linh Pham/ Getty Images
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Vietnamese walk past a model of an airplane at the Vietnam People's Air Force Museum on in HanoiLinh Pham/ Getty Images
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US Secretary of State John Kerry (L) arrives at a press conference at the International Convention Center in HanoiLuong Thai Linh/ AFP
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A man carries his daughter near Vietnam's presidential palace as US President Barack Obama begins his three-day visitLinh Pham/ Getty Images
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A man stands in front of the B-52 crash site in Huu Tiep Lake in HanoiLinh Pham/ Getty Images
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US President Barack Obama shakes hands with locals in a shopping district in HanoiJim Watson/ AFP
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A crowd cheering near Vietnam's presidential palace as US President Barack Obama begins his three-day visitLinh Pham/ Getty Images

Lifting the ban on arms sales is likely to upset China, a country which is becoming territorial with Vietnam. It sees US support for rival South China Sea applicants like Vietnam and the Philippines as interference and an attempt to establish hegemony in the region. Barack Obama said that Washington would stand with partners to ensure freedom of navigation and flight in the South China Sea and, without mentioning China by name, said big nations should not bully smaller ones.

Vietnam's President Tran Dai Quang has described Barack Obama's first visit to the country as the arrival of a warm spring after a cold winter. Yet Obama has expressed concerns that despite great strides made by Vietnam, Washington is worried about their limits on political freedom.

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US President Barack Obama meets with Communist Party of Vietnam General Secretary Nguyen Phu Trong at the Communist Party of Vietnam's Central Office in HanoiJim Watson/ AFP
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US President Barack Obama (C) waves after eating dinner at Bun cha Huong Lien with CNN's Anthony Bourdain in HanoiJim Watson/ AFP
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US President Barack Obama walks toward Air Force One upon his departure from Noi Bai international airport in Hanoi where he will travel to Ho Chi Minh CityLuong Thai Linh/ AFP
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A tuk tuk passes a crowd cheering near Vietnam's presidential palace in HanoiLinh Pham/ Getty Images
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A poster of US President Barack Obama in front of a tailor shop on May 23, 2016 in HanoiLinh Pham/ Getty Images
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US President Barack Obama waves as he boards Air Force One upon his departure from Noi Bai international airport in Hanoi, where he is travelling to Ho Chi Minh CityLuong Thai Linh/ AFP