In a radio address, Samak also refused to dissolve Parliament and said he will stay in office to "protect democracy," the Thai News Agency reported.
Adding to Samak's political headaches was the resignation of his Foreign Minister Tej Bunnag.
Samak ordered a state of emergency in the capital Tuesday following clashes between supporters and opponents of his government. Critics say the government is only a proxy for former Prime Minster Thaksin Shinawatra, who was deposed in a coup in 2006 in face of corruption charges.
In his address, Samak refused to heed the demands of anti-government protesters led by the People's Alliance for Democracy, who have been seeking his resignation since May.
He said he accepted the foreign minister's resignation because Tej's wife wasn't well, the report said.
The Bangkok Post, however, reported Tej's departure could hasten the government's fall as he is also an adviser to Thailand's revered king. It quoted diplomatic sources as saying he quit as he became upset with recent political events.
The People's Alliance party has refused to talk with the government unless Samak resigns.