U.S. Secretary of State Rex Tillerson on Tuesday pressed Thai leaders for more action on North Korea during the highest level visit to Thailand by a U.S. official since a military coup in 2014 soured relations with the United States.
Tillerson's top priority has been urging Southeast Asian countries to do more to cut funding streams for North Korea.
The United States believes North Korean front companies are active in Thailand and is trying to encourage the Thais to shut them down, Assistant Secretary for East Asian and Pacific Affairs Susan Thornton told reporters aboard Tillerson's plane.
The companies are using Bangkok as a regional hub and change their names frequently, she said.
Before meeting Tillerson, Prime Minister Prayuth Chan-ocha said Thailand would support a U.N. resolution on new sanctions on Pyongyang over its missile tests. But he made no mention of specific action.
The United States was encouraging Thailand to take as many North Korean refugees as it can handle, Thornton said. Reuters reported exclusively last week that the number of North Koreans slipping illegally into Thailand has surged in recent months.
Thailand's own politics and human rights record were also in focus, as Washington strengthens relations with its oldest ally in the region after they were downgraded following the coup.
"We want Thailand to emerge as a strengthened democracy that respects and guarantees human rights and fundamental freedoms at home and plays a leading role in advancing regional security and prosperity," a U.S. embassy spokesman said.