The United States defence secretary, Chuck Hagel, has called on Thailand's military leaders to restore democratic rule soon, contrary to what the regime has promised.
Thailand's new military ruler, General Prayuth Chan-ocha, has said he does not expect to hold elections for at least a year.
In a televised address to the nation, the general said time is needed to reconcile, draft a new constitution and mend Thailand's democratic system.
Speaking at a security conference in Singapore, Mr Hagel said the Thai military should end restrictions on free expression, release detainees and restore power to the people through elections.
He was speaking a week after the democratically-elected civilian government was overthrown following months of political wrangling, the BBC reports.
Meanwhile, Australia says it is reducing its engagement with the Thai military and will lower its level of interaction with the army's leadership.
In a joint statement, Foreign Minister Julie Bishop and Defence Minister David Johnstone said the government continues to have grave concerns about the actions of the military in Thailand.
Three military activities with Thailand have been postponed and Canberra has also put in place a mechanism to prevent the leaders of the coup from travelling to Australia, the ABC reports.