"We will negotiate in all forums and use all channels ... to communicate and create understanding on the issues (with the U.S)," Keerati Rushchano, acting director-general of the Department of Foreign Trade, told a news conference.

He also said the government will support Thai exporters in efforts to diversify their markets.

"There will be trips for business to explore new markets in the Middle East, Eastern Europe, Africa and secondary cities in China and India where markets are not so familiar with Thai products," Keerati said.

On Friday, the U.S. suspended duty-free treatment of Thai imports worth $1.3 billion, including seafood products, under its Generalized System of Preferences (GSP) programme, saying Thailand did not "afford workers in Thailand internationally recognised worker rights".

The loss of duty-free treatment would cause Thai products incur duties between 1.5 billion baht to 1.8 billion baht ($59.6 million) a year, the Thai commerce minister said on Sunday.

CP Foods Pcl, a giant Bangkok-based food company, said just one of its exported products, shrimp wonton noodles, would be affected by the U.S. move. Thai Union Group Pcl, the world's largest producer of canned tuna, said the decision would not have any material impact on its business.

At 0840 GMT Monday, shares of CP Foods were down 2% and those of Thai Union were off 3.57%.

On Sunday, the government said that it was ready to negotiate the issue of labour unions for migrant workers.

(Reporting by Chayut Setboonsarng; Editing by Richard Borsuk)