The Chinese commerce ministry said on Thursday U.S. tariffs were "vile", "unilateralist" and exacerbated global trade tensions, after President Donald Trump threatened to heap import duties on major U.S. trading partners.

China is ready to work with other countries to jointly respond to the challenges of unilateralism and trade protectionism, He Yongqian, a ministry spokesperson, said at a regular news conference, when asked to comment on planned U.S. tariffs on Canada and Mexico.

Trump on Monday suspended his threat of 25% tariffs on Mexico and Canada for 30 days after the two neighbouring countries said they would bolster border enforcement efforts.

But the 10% U.S. tariffs on Chinese goods went ahead on Tuesday, with Trump warning he might increase them.

The United States says China is the chief source of the precursor chemicals synthesised into fentanyl in Mexico. But China says it has taken significant steps to crack down on the chemicals and illicit drug trade, and that it would challenge the tariffs at the World Trade Organization.

China is willing to resolve the issue through dialogue but will take necessary measures to defend its own rights and interests against unilateralist "bullying", the Chinese commerce ministry spokesperson said.