WASHINGTON >> Tariffs on imports from Canada and Mexico will go into effect on March 4 “as scheduled,” President Donald Trump said Thursday morning, claiming that those countries were still not doing enough to stop the flow of drugs into the United States.

China will also face an additional 10% tariff next week, on top of the 10% he imposed earlier this month, the president wrote in a post on Truth Social.

“Drugs are still pouring into our Country from Mexico and Canada at very high and unacceptable levels,” he said. “A large percentage of these Drugs, much of them in the form of Fentanyl, are made in, and supplied by, China.” He added that the levies were necessary until the flow of drugs “stops, or is seriously limited.”

In the Oval Office on Thursday afternoon, Trump said progress had been made on reducing the flow of migrants, but said he hadn’t seen that same progress on drugs, particularly fentanyl.

“The drugs continue to pour into our country, killing hundreds of thousands of people,” he said.

Trump threatened to impose tariffs on all products from Canada, Mexico and China in early February, an effort he said was aimed at stemming the flow of both migrants and drugs. But after Mexico and Canada promised measures like sending more troops to the border and, in the case of Canada, appointing a “fentanyl czar,” Trump paused their tariffs for one month.

He moved ahead with imposing a 10% tariff on all products from China, on top of those already in place, which prompted China to retaliate with its own tariffs on U.S. goods.

Now, Trump said Thursday, he will proceed with an additional 10% tariff on Chinese goods, a decision he had not previously announced. Those tariffs will be added on top of the 10% to 25% tariffs that Trump imposed on more than $300 billion of products from China in his first term, which are largely still in effect.

Since Trump revealed plans for tariffs on the three countries in late January, the Mexican and Canadian governments have been furiously working to defuse tensions and persuade Trump that they have been working to police their borders.

China’s efforts, in contrast, appear to have been more muted. Trump’s threat of an additional tariff could be an effort to bring the Chinese to the table for more negotiations.

Additional tariffs on the country’s three biggest trading partners would only add to the economic strain that has begun to emerge from Trump’s flurry of actions. Companies that import car parts, medical devices, vegetables and clothing into the United States are once again grappling with how they will absorb the additional costs.

Three textile associations issued a joint statement Thursday urging the president to reach a deal with Mexico and Canada and avoid imposing the 25% tariff, arguing that the three countries had an integrated North American supply chain that generated $20 billion in trade and supported more than 1.6 million jobs.