BEIJING (Reuters) - Beijing said on Friday it opposed President Donald Trump's latest threat to slap an extra 10% duty on Chinese imports, accusing the U.S. of "shifting the blame" on the flow of fentanyl and promising retaliation to protect its interests.

China's Commerce Ministry said the country has some of the world's strictest anti-drug policies and highlighted the risks new tariffs would bring to global supply chains.

Trump said on Thursday his proposed 25% tariffs on Mexican and Canadian goods will take effect on Tuesday, along with the 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.

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 tariffs of up to 60% when Trump took office.

"China has 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. "This time, (the U.S.) once again is threatening additional tariffs. Such behaviour is purely 'shifting blame and shirking responsibility,' which is not conducive to solving its own problems."

Analysts say Beijing still hopes to strike a deal with the Trump administration, but with trade talks not materialising yet and the White House ramping up signs it is preparing for a wider economic decoupling from China, the prospect of a rapprochement between the world's top two economies remains unclear.

"There's been a lot of motion, but it's still not clear exactly what the Trump administration's fundamental goal is with respect to China," said Christopher Beddor, deputy China research director at Gavekal Dragonomics.

The Commerce Ministry said it hoped to return to negotiations with the U.S. as soon as possible, warning that failure to do so could trigger retaliation.

"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."

Trump told reporters in the Oval Office on Thursday he decided to add the extra tariffs on China and stick to the Tuesday deadline for Canada and Mexico given what his administration sees as insufficient progress on curbing fentanyl flows into the country.

"There are ongoing discussions with the Chinese, Mexico and Canada," a White House official told Reuters. "We've gotten a good handle on the migration issue, but there are still concerns on the other issue of fentanyl deaths."

China's Public Security Ministry said on Friday it had added seven new precursor chemicals to a domestic control list and 24 new precursor chemicals to an export control list. It said that it had cracked 151 cases of drug-making materials and seized 1,427.4 tons of drug-making materials in the past year, without specifying whether these were related to fentanyl.

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