BANGKOK - Thailand's negotiations with Washington on steep trade tariffs were postponed because the United States has asked Bangkok to review important issues, Prime Minister Paetongtarn Shinawatra said on Tuesday.

A new meeting date was being scheduled, she said. The previous date for talks was April 23.

Thailand is among the Southeast Asian nations hardest hit by US President Donald Trump's measures, facing a 36 percent tariff if a reduction cannot be negotiated before a global moratorium expires in July.

"We're not too slow and we are reviewing issues, including our tariffs that may be adjusted appropriately," Paetongtarn said, adding that Thai agriculture exports and additional imports were being examined.

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The United States was Thailand's largest export market last year, accounting for 18.3 percent of total shipments, or $54.96 billion. Washington has put its deficit with Thailand at $45.6 billion.

"We are consulting academics and all parties and doing our best in this situation," she added.

"We are protecting the agricultural interests as much as possible," she said, adding negotiations should be mutually beneficial.

Thai rice exports fell 30 percent in the first quarter, opens new tab and could come below full-year forecasts of 7.5 million metric tons over the tariffs, according to rice the export association

Last year, Thailand shipped 9.94 million tons of rice worth 225.65 billion baht, with the US being its third-largest market by volume.

Thailand's Finance Minister Pichai Chunhavajira, who had been due to join the talks in Washington, said that despite the postponement of US negotiations, talks were still ongoing on the working level. He said he had no plans to travel to the United States soon.