Sri Lanka, June 4 -- Sri Lanka's export sector could face a new challenge in the United States market after Washington proposed additional tariffs on imports from countries it says have failed to adequately prevent the entry of goods produced through forced labour.

This places the island nation among 54 economies targeted under a sweeping trade investigation.

The development has potential implications for Sri Lanka's apparel industry, which has built much of its international reputation around ethical manufacturing practices and compliance standards. At present, it relies on the United States as its single largest export destination.

Accordingly, the Office of the United States Trade Representative (USTR) has proposed an additional 12....