Prime Minister Stephen Harper and his Thai counterpart announced the start of free-trade talks Friday as Harper continues to tout Canada as a viable business partner for rapidly expanding Asian economies.

Harper is on the first leg of his swing through Thailand, Japan and South Korea -- his second trip to Asia in two months.

CTV's Daniele Hamamdjian, travelling with the prime minister, said Harper is anxious to build economic bridges with Asia.

"Thailand is the fastest growing economy in Southeast Asia, one of the fastest growing in the world with 67 million people, and Stephen Harper says Canada would have a lot to gain and vice-versa. And so they announced today they are exploring the possibilty of a free-trade agreement," she said from Bangkok.

However, Hamamdjian said some are critical of the announcement, saying Canada has been in free-trade talks with a number of countries for years, with few tangible outcomes.

Harper announced the talks alongside Thai Prime Minister Yingluck Shinawatra.

"Our Government is working hard to create jobs, growth and long-term prosperity in Canada by expanding free and open trade with the world," Harper said in a statement.

"A free trade agreement with Thailand -- one of the fastest growing economies in the world -- stands to significantly benefit farmers and businesses across Canada."

Shinawatra welcomed Ottawa's renewed interest in Thailand, pointing out it has been 15 years since a Canadian minister last made an official visit to the nation.

"This visit not only highlights the strong relations between our two countries but also reaffirms Canada's re-engagement in Asia," Shinawatra said after the announcement of exploratory trade talks.

The Canadian government will also engage "Canadians and stakeholders, including provincial and territorial partners, on the scope of a possible free-trade agreement with Thailand," the statement said.

A backgrounder from the Prime Minister's Office said Thailand is Canada's largest merchandise trading partner. In 2011, that trade totalled close to $3.5 billion, an increase of 14.8 per cent over the previour year.

During his trip to Thailand, Harper also visited Bangkok's Grand Palace and paid respects to Bhumibol Adulyadej, the ailing King of Thailand.

Harper is expected to focus on building trade relations in Thailand and Japan. Early next week, when Harper arrives in South Korea, the focus will shift as leaders from 53 nations meet to discuss nuclear security and terror threats. The talks are also expected to touch on Iran and North Korea and their nuclear programs -- though the subject is not officially on the agenda.

Pyongyang issued a warning ahead of the talks, saying any condemnation of its program would be viewed as a "declaration of war."

Former prime minister Jean Chretien led the last official visit to Thailand.