April 16 (UPI) — Hong Kong’s postal service announced Wednesday it will suspend the handling of U.S.-bound packages, due to President Donald Trump‘s tariff hikes targeting China.

The suspension of U.S.-bound packages by sea went into effect immediately on Wednesday, with U.S.-bound packages by air to be suspended April 27, Hongkong Post said in a statement.

The postal service explained that the decision was in response to Trump’s order earlier this month to end duty-free de minis treatment for China and Hong Kong starting May 2, which had waived duties for international shipping valued at $800 or less.

“The U.S. is unreasonable, bullying and imposing tariffs abusively,” Hongkong Post said. “Hongkong Post will definitely not collect any so-called tariffs on behalf of the U.S. and will suspend the acceptance of postal items containing goods destined to the U.S.”

The postal service is warning the public to “be prepared to pay exorbitant and unreasonable fees” for sending items to the United States, though other postal items, such as documents, will not be affected.

Trump has used tariffs as a tool to reduce trade deficits and as a negotiation tactic to force concessions from trading partners.

He has imposed tariff hikes of 145% on Chinese exports and, earlier this month, was set to impose so-called reciprocal tariffs on dozens of other countries before flip-flopping and issuing a 90-pause the tax increase as stock market took a beating.

The tariffs on China have taken effect, and Beijing has responded with its own.

On April 2, Trump signed an executive order to eliminate China’s de minimis treatment, with the White House stating it was “closing loopholes in the tariff system.”

In February, Hongkong Post suspended the acceptance of U.S.-bound goods after Trump initially announcing a 10% tariff on Chinese exports. Days later, the postal service said it had resumed accepting U.S.-bound packages after Washington clarified that the additional tax would not apply to postal items.