For the second time this year, Prime Minister Stephen Harper is en route to Asia for an official visit.

Harper left Ottawa Wednesday morning, headed to Bangkok at the invitation of his Thai counterpart, Prime Minister Yingluck Shinawatra.

Coming on the 50th anniversary of diplomatic relations between Canada and Thailand, as well as the 35th anniversary of Ottawa's dialogue with Association of Southeast Asian Nations (ASEAN) of which Thailand is a member, Harper's trip is intended to celebrate the two countries' bilateral relations.

After his official welcome on Friday, Harper is expected to raise a number of issues from Canadian oil and energy resources to human smuggling and terrorism in the Asia-Pacific region during his meeting with Yingluck.

But, according to a senior fellow with the Asia Pacific Foundation of Canada, improving trade is likely at the top of Harper's agenda.

In an interview from Washington Wednesday, Amitav Acharya noted that ASEAN, of which Thailand is a member, is poised to become an economic community by 2015.

"That means a reduction of barriers to trade," Acharya told CTV News Channel, "and that gives Canada an opportunity to increase its exports."

Considering that ASEAN's 10 member countries boast of 601 million citizens and a combined GDP second only to China on the world stage, Acharya said the potential market is too big to ignore.

The prime minister is expected to touch on the free trade issue as well as the lifting of a ban on certain Canadian beef products when he heads to Japan Sunday and Monday, before wrapping up the Asian swing in South Korea next Tuesday.

On his final stop of the three-nation tour, Harper plans to attend a nuclear security summit of 53 world leaders in the South Korean capital Seoul.

A spokesman for the Prime Minister's office, Andrew MacDougall, expects the subject of rogue nations' nuclear weapons capabilities to come up at the summit, but he says attendees also have a broader agenda in mind.

"It's unavoidable the subject will be raised, but I think the summit will work at stopping proliferation and securing (nuclear materials)," MacDougall told The Canadian Press, suggesting atomic energy's peaceful applications will also be on the agenda.

While in Japan, Harper also plans to pay a visit to the tsunami-stricken region of Sendai.

Harper's three-nation Asia tour comes less than a month after a trip that focused on improving diplomatic and trade relations between Canada and China.