Hong Kong announced Wednesday that its postal service would no longer send packages to the United States, in response to the White House’s plan to charge tariffs on small, low-value parcels from the city.

The move comes before President Trump’s planned imposition of new tariffs on small packages sent to the United States from Hong Kong and China.

Hong Kong’s postal service will stop handling packages coming from or going to the United States amid an escalating trade war between the world’s two largest economies.