U.S. President Donald Trump spoke to the leaders of Thailand and Singapore on Sunday in separate phone calls about the security situation in the Asia-Pacific region at a time of rising tensions with North Korea and invited both to visit Washington, the White House said.

Thailand Prime Minister Prayuth Chan-ocha, a former general, heads a military-dominated government that took power in a 2014 coup. His government had strained relations with Trump's predecessor, Barack Obama.