KUALA LUMPUR (Reuters) -The United States expects to finalise trade deals with more Southeast Asian countries in the coming months, U.S. Trade Representative Jamieson Greer said during a meeting with regional counterparts on Wednesday.

Greer was speaking in Kuala Lumpur at the start of a meeting with economic ministers from the 10-member Association of Southeast Asian Nations, amid concerns within the export-reliant bloc over the impact of U.S. tariffs on their economies.

Tariff rates have been set at 19% and 20% for most of the region. Laos and Myanmar have been hit with a 40% rate, while Singapore has a 10% tariff.

Greer said talks with respective countries on the levies have been progressing well, with agreements to be finalised "in the coming months or even weeks, for some."

"We believe that there are many areas where our interests align, and we can work together to achieve shared goals of bringing reciprocity and balance to the global trading system," he said.

Indonesia and Vietnam have already negotiated new trade deals with the United States, securing lower tariffs in the process.

But Vietnam, the world's sixth-largest exporter to the United States, risks losing $25 billion annually as a result of the 20% tariff imposed on its goods, which would make it the worst-hit economy in the region, according to estimates released by the United Nations Development Programme.

Wednesday marked Greer's first meeting with the ASEAN bloc, whose members have largely engaged in separate negotiations with the United States on the issue of tariffs.

But the grouping may be driven to take a more unified position amid risks of steeper sectoral tariffs on industries such as semiconductors, a significant contributor to economies like Thailand, Malaysia, and Vietnam.   

U.S. President Donald Trump said last month he would set a tariff of about 100% on semiconductors, but it would not apply to companies that are manufacturing in the United States or have committed to do so.