David Cohen, deputy director of the Central Intelligence Agency of the United States, made an unscheduled visit to Government House on Friday.
Mr Cohen met Prime Minister Prayut Chan-o-cha at Thai Khu Fa building at 9.30am. Their meeting lasted about 45 minutes.
He also talked with Deputy Prime Minister Prawit Wongsuwon at Command Building 1 and Gen Supot Malaniyom, secretary-general of the National Security Council, at the Red Building.
Security guards blocked reporters from covering the meetings and they could only take photos of the visitor from a distance.