Hun Sen has maintained communication with former Thai prime minister Thaksin Shinawatra, who returned to his native country Thursday after 18 months in exile.
"Since the coup toppled him, phones calls were exchanged," Hun Sen said Thursday. "It's very normal."
He called Thaksin an old friend, and deflected reports Thaksin had come to visit him before his return to Thailand.
If he were to come, Hun Sen said, "I would receive him without keeping it silent."