U.S. President Obama
US President Obama waves to photographers as he arrives at Don Muang international airport in Bangkok - Reuters

US President Barack Obama has begun his three-day tour of Asia with a visit to Thailand.

The tour, designed to foster relations with Asian countries, is Obama's first foreign trip since his re-election as president. Obama will also make a historic trip to Myanmar.

Obama, who has proclaimed himself America's first "Pacific president", has landed in the Thai capital Bangkok after a slight delay. He will hold talks followed by a news conference with Thai Prime Minister Yingluck Shinawatra before heading to Myanmar on Monday, 19 November.

Obama is likely to discuss a range of issues including terrorism, trade, and control of drug trafficking with Shinawatra. Washington sees Bangkok as a key ally in helping to realign US economic and security policies to counter the growing clout of China in the region.

"Allies are the cornerstone of our rebalancing effort in Asia. Thailand is actually the oldest treaty ally of the United States, an ally since 1954 and a key partner in Southeast Asia," said Ben Rhodes, a US deputy national security adviser.

During his landmark visit to Myanmar (which the US continues to call Burma), Obama will meet its President Thein Sein and leading opposition figure Aung San Suu Kyi. He will be the first US president to visit the resources-rich country.

His visit has been criticised by human rights groups who claim it gives recognition to the quasi-civilian government in Myanmar which is yet to contain the ethnic clashes in the country.

The White House has said that his visit is an approval of the transition in the country towards democracy and should not be viewed as a "victory celebration" by the Myanmar government.

The country was under military rule for decades before a political transition, which began in 2008 and resulted in the dissolution of the military junta in March 2011.

From Myanmar, Obama will proceed to the East Asia Summit in Cambodia.