WASHINGTON (Reuters) -U.S. President Donald Trump said on Thursday that his proposed 25% tariffs on Mexican and Canadian goods will go into effect on March 4 as scheduled because drugs are still pouring into the U.S. from those countries.

Trump also said he would impose an additional 10% duty on Chinese goods on that day. This would appear to be on top of the 10% tariff that he levied on Feb. 4 on imports from China.

Trump said drugs were still coming into the U.S. at "very high and unacceptable levels," with a large percentage of them the deadly opioid fentanyl.

"We cannot allow this scourge to continue to harm the USA, and therefore, until it stops, or is seriously limited, the proposed TARIFFS scheduled to go into effect on MARCH FOURTH will, indeed, go into effect, as scheduled," Trump said in a post on his Truth Social media site. "China will likewise be charged an additional 10% Tariff on that date."

The statement cleared up some confusion on Wednesday over deadlines for the punishing tariffs on Canadian and Mexican goods that Trump has threatened over the fentanyl crisis and U.S. border security.

Trump's comments on the matter during his first cabinet meeting on Wednesday seemed to suggest that he may push the deadline back for about one month until April 4.

Comments from Trump administration officials indicated that the April deadline was for Trump's "reciprocal tariffs" matching import duty rates of other countries and offsetting their other restrictions. His trade advisers consider European countries' value added taxes to be akin to a tariff.

Kevin Hassett, the top White House economic adviser, told CNBC television that Trump would determine new tariffs after a study is completed by April 1.

"The schedule is that there's a study coming out on April 1, and after that the president is going to decide what to do about tariff policies for all countries," he said, but specifically mentioning Mexico and Canada.

TARIFF, BORDER TALKS

Meanwhile, Canadian and Mexican officials were due to meet with Trump administration counterparts in Washington on Thursday and Friday to try to forestall the tariffs, which could deal a serious blow to a highly integrated North American economy.

Mexican Economy Minister Marcelo Ebrard will meet with newly confirmed U.S. Trade Representative Jamieson Greer on Thursday and Commerce Secretary Howard Lutnick on Friday.

In Canada, Public Safety Minister David McGuinty said on Thursday that the progress Canada has made on tightening security along the border with the United States and combating drug smuggling should satisfy the Trump administration.

"The evidence is irrefutable - progress is being made," McGuinty said in televised remarks to reporters in Washington ahead of two days of talks with U.S. officials.

"In my view, any test that was put on Canada in terms of showing progress and meeting standards for the border - I believe those have been met," he said.

The Canada Border Services Agency said in a statement that it was launching a targeted, cross-country initiative to intercept illegal contraband arriving and leaving the country, with a focus on fentanyl and other synthetic narcotics.

China, in a letter to U.S. Trade Representative Jamieson Greer, said China and the United States should address concerns in economic and trade fields through equal dialogue and consultation.