BANGKOK: Thailand's prime minister has accepted President Donald Trump's invitation to visit the United States as the US leader made an unexpected diplomatic initiative toward his Southeast Asian counterparts.

Trump telephoned Thailand's Prime Minister Prayuth Chan-ocha and Singapore Prime Minister Lee Hsien Loong on Sunday to reaffirm traditional close relations and invite them for meetings. The invitations followed an offer made late Saturday to Philippine President Rodrigo Duterte.

Prayuth's office said Monday he had accepted Trump's invitation, while a Singapore Foreign Ministry statement said the two looked forward to seeing each other soon.

Human rights groups have criticised Prayuth for seizing power in a coup and curbing democratic rights, while Duterte is scorned for his deadly war on drugs. However, Washington has strategic concerns in countering Chinese influence in Southeast Asia.