WASHINGTON (AFP) - The United States said Friday it has suspended US$3.5 million (S$4.4 million) in military assistance for Thailand, about one-third of its aid to the ally, after the army seized power.

State Department spokesman Marie Harf said that the United States was also reviewing the rest of US aid to Thailand - which totaled some US$10.5 million in 2013 - to look for further cuts.

"We have already suspended approximately US$3.5 million" in funding and training for the Thai military, Harf told reporters.

"We are reviewing all programs to determine other assistance which we may suspend," she said.

Harf said that the United States was looking through its allocated funding for international bodies including the 10-nation ASEAN bloc to identify money directed to Thailand.

The United States has contacted junta leaders to deliver the message, Harf said.

"We urge the immediate restoration of civilian rule, a return to democracy and, obviously, respect for human rights during this period of uncertainty," she said.

Under domestic law, the United States is obligated to suspend assistance to foreign militaries that overthrow elected governments.

Secretary of State John Kerry earlier strongly condemned Thursday's coup, saying there was "no justification" and that the move would have "negative implications" for relations.

Kerry urged the restoration of a civilian government, respect for press freedom and early elections.

Thailand is the oldest US ally in Asia and provided critical support in the Vietnam and Korean wars.