BEIJING, June 7 (Reuters) - Two of the world's largest solar panel producers said they were suspending some production in Southeast Asia this week, after a U.S. tariff reprieve on solar panels from some Southeast Asian countries expired.

China's Longi Green Energy Technology said on Friday that it had suspended production at a battery plant in Vietnam, while Trinasolar said on Thursday that facilities in Thailand and Vietnam would enter a maintenance shutdown.

Longi said its further decisions would follow an evaluation of market conditions. The company said the production halt in Vietnam would have limited impact on its operating performance, given the country accounted for less than 10% of Longi's total battery production capacity in 2023.

Longi also said that some of its other plants in Southeast Asia that had been reported closed by media remained in operation.

While not specifying which media reports it was referring to, it said its plants in Malaysia and component plants in Vietnam were in operation.

The news comes after Longi said on Tuesday it would "adjust" production citing a "complex industry environment" but that it remained optimistic about the sector's future.

A two-year U.S. tariff holiday on solar panels from four Southeast Asian countries expired on Thursday.

The tariffs aim to target shipments by companies found to be dodging U.S. duties on Chinese goods by finishing panels in Malaysia, Thailand, Cambodia and Vietnam.

Separately, rival panel producer Trinasolar said in a statement to Reuters on Thursday that its facilities in Thailand and Vietnam, which primarily serve the U.S. market, would enter an annual mid-year maintenance shutdown.

Demand in the U.S. market is currently experiencing some short-term fluctuations due to policy changes, Trinasolar said, adding that its production plans would depend on industry and market conditions.

Trinasolar also said it had new cell and module capacity in Indonesia, which is not covered by the U.S. tariffs, under construction with the start of operations expected in the third quarter. Indonesian state-owned utility PT PLN (Persero) is its joint venture partner.

"In the long run, Trinasolar aims to enhance its market position and to mitigate international trade risks through a broader and deeper diversified layout and localised operations," the company said.

The United States last month also unveiled steep tariff hikes on Chinese imports including solar panels, electric vehicles and batteries. However, those are anticipated to have little impact on Chinese producers because the U.S. imports few solar panels directly from China. (Reporting by Amy Lv, Colleen Howe, and Siyi Liu in Beijing Editing by Tomasz Janowski)