BANGKOK (Reuters) -The effect on Thailand from the United States' tariff policy will be prolonged, with a very high degree of uncertainty over the potential impact, its central chief bank said on Friday.

The impact will be more clear in the second half of the year, Bank of Thailand Governor Sethaput Suthiwartnarueput told a press briefing. 

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

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

The manufacturing sector will be hit the hardest, but the impact will not be as bad as during the pandemic, Sethaput said, adding there were also concerns over a flood of imports into Thailand from diverted trade.