WASHINGTON : The US government has joined the chorus of nations in reacting to the violence in Thailand.

It condemned the violence by anti-government protestors and urged its citizens to exercise caution while in the Kingdom.

In the first public comments made by the Obama administration about the events over the Thai New Year, State Department spokesman Robert Wood urged an end to violence by the "red shirt" demonstrators.

"We are watching the situation in Thailand very closely and condemn this unacceptable violence by the protesters. And we call on the protesters and their leaders to forswear any additional use of violence, to exercise their right to assembly, but to do so peacefully," said Wood.

The comments came after East Asian leaders were forced to abandon a planned summit at the resort of Pattaya, because the venue was stormed by protesters.

US analysts said Thailand's reputation as an international trade, investment and travel hub is being eroded.

"It already had an impact. Tourism is down by about 30 per cent. Air traffic has also been down about 30 per cent. Other airports in Singapore, Hong Kong, and to a lesser extent Malaysia, have offered packages for other air carriers to use their places as a hub," said John Brandon at Asia Foundation.

The US embassy in Bangkok is advising its citizens to avoid protests and exercise caution throughout the city. But there has been no specific warning to avoid travelling there.

What's not yet clear is whether Secretary of State Hillary Clinton will still attend the ASEAN Regional Forum in Bangkok in July as promised. - CNA /ls