US President Donald Trump pledged on Tuesday to hit the European Union with tariffs, adding that a 10 percent duty on Chinese imports could also come as soon as February 1.

Trump voiced his latest tariff threats in remarks to reporters at the White House a day after taking office.

"They treat us very, very badly. So they're going to be in for tariffs," Trump said of the EU. "You can't get fairness unless you do that."

A day earlier, Trump accused the bloc of not importing enough American products, saying he would "straighten that out" by imposing duties or by urging for more oil and gas purchases.

Regarding China, Trump on Tuesday reiterated his threat to impose a 10 percent tariff, saying it was "based on the fact that they're sending fentanyl to Mexico and Canada."

When asked how soon these tariffs could be enacted, he added: "Probably February 1st is the date we're looking at."

This was the same date he earlier said he could impose 25 percent tariffs on Canada and Mexico, accusing them of failing to stop illegal immigration and fentanyl trafficking into the United States.

The EU's economy commissioner vowed this week that the bloc was ready to defend its interests.

Speaking at an annual meeting of global elites in Davos, Switzerland, EU chief Ursula von der Leyen declared that Europe was ready to negotiate with Trump, while maintaining that Washington remained an important partner.

The EU's "first priority will be to engage early, discuss common interests, and be ready to negotiate" with Trump, she said.

"We will be pragmatic, but we will always stand by our principles, to protect our interests and uphold our values," she said.

In November, following Trump's announcement of additional tariffs, mainland media accused him of blaming China for Washington's failure to address the fentanyl crisis.

China Daily said scapegoating others cannot end the drug crisis in the US, while the Global Times urged Washington not to take China's goodwill for granted regarding anti-drug cooperation.

Beijing has spoken out against protectionism, saying no one wins in a trade war. (AFP)