The US is mulling the fate of the annual "Cobra Gold" war games it cosponsors with Thailand, after stripping millions of dollars in aid from its ally over the military coup.
With the Thai military reluctant to ease its grip on power, a US Department of Defense spokesman told reporters that the annual live-fire exercise -- the biggest such US operation in Asia -- was under scrutiny.
"The Department of Defense is currently reviewing all of its engagements to make sure they comply with government policy," said Major David Smith, a Defense Department spokesman. "They are looking at it."
The US stripped US$24 million in military aid from Thailand last week, in protest at the coup by top generals on Sept. 19 which deposed prime minister Thaksin Shinawatra.
The sanctions jolted years of close links between US forces and Thailand.
Some aid deemed crucial to US national security was spared, notably in the field of counterterrorism, in which the kingdom has emerged as a low-key, yet valued partner in the US battle against al-Qaeda.
"Cobra Gold" does not automatically fall foul of laws which bar the US from supplying aid to a foreign government which has overthrown a democratic administration in a military coup, officials said.
But the US military would likely face heavy criticism for going through with an operation co-hosted with a military force instrumental in overthrowing an elected prime minister.
Equally, however, Washington is unlikely to want to cede any ground to other powers, especially China, which has been expanding its diplomatic and military engagement in Southeast Asia.
The latest "Cobra Gold" exercise in May was the 25th and involved forces from the US, Thailand, Singapore, Indonesia and Japan, as well as observers from many other nations.
On Friday, Washington underlined its continuing concern over the situation in Thailand.
State Department spokesman Sean McCormack withheld formal comment on reports that Thailand's ruling junta intended to choose retired general Surayud Chulanont, 63, to replace Thaksin, pending confirmation of the appointment.
"Somebody with close ties to the military is going to have to at least overcome the perception that they are maintaining a close relationship with the military and may be not acting in defense of Thai democracy," McCormack said.
The junta, with the backing of King Bhumibol Adulyadej, pledged after the coup to appoint a new civilian premier within two weeks to guide Thailand towards elections next October.
But the military is instead now expected to appoint Surayud to serve right up until the polls.
McCormack said the US continued to watch developments in Thailand "very closely: Who is appointed as prime minister, that person's background, the policies that they pursue."
Coup leader General Sonthi Boonyaratglin has indicated that the junta will not be disbanded once the new interim leader is named.