BEIJING (Reuters) - China on Friday said it opposed President Donald Trump's latest threat to slap an extra 10% duty on Chinese imports over deadly drug flows into the U.S., accusing the White House of "shifting the blame" and taking steps to destabilise global supply chains.

Trump said on Thursday his proposed 25% tariffs on Mexican and Canadian goods will take effect on Tuesday, along with an extra 10% duty on Chinese imports.

The fresh China tariffs, in addition to the 10% tariff levied on Feb 4, coincide with the start of China's annual parliamentary meetings on Wednesday, a set-piece political event where Beijing is expected to unveil its main economic priorities for 2025.

"We have repeatedly stated that unilateral tariffs violate World Trade Organization rules and undermine the multilateral trading system," a commerce ministry spokesperson said in a statement.

"China has one of the strictest and most thoroughly enforced anti-drug policies in the world," it said. "Now, (the U.S.) once again is threatening additional tariffs. This behaviour is nothing more than shifting the blame and shirking responsibility."

The announcement also leaves Beijing less than a week to publish countermeasures, as the Trump administration shows signs of a hardening stance towards its strategic rival despite backing down on the threat of 60% tariffs when Trump took office.

"China urges the U.S. not to repeat its mistakes and to return to the correct path of resolving disputes through equal dialogue as soon as possible," the statement said.

"If the U.S. insists on proceeding with this course of action, China will take all necessary countermeasures to safeguard its legitimate rights and interests."

(Reporting by Joe Cash; Editing by Shri Navaratnam and Lincoln Feast.)