U.S. President Donald Trump has accused China and Europe of manipulating their currencies, raising fears that Washington will carry out repeated threats to impose tariffs on goods from the European Union.

"Accusations of Eurozone currency manipulation are ... flying from the White House with talk of tariffs on the EU and European countermeasures heating up trade tension between the two regions," said Robert Carnell, chief economist at Dutch bank ING.

In a tweet on Wednesday morning U.S. time, Trump said: "China and Europe playing big currency manipulation game and pumping money into their system in order to compete with USA."

He then called for easier monetary policy, adding that the U.S. should "match" the monetary policies of China and Europe.

Trump Tweet: China and Europe playing big currency manipulation game and pumping money into their system in order to compete with USA. We should MATCH, or continue being the dummies who sit back and politely watch as other countries continue to play their games - as they have for many years!

In late May, the U.S. Commerce Department had proposed tariffs on goods from countries found to have undervalued their currencies against the dollar.

"This change puts foreign exporters on notice that the Department of Commerce can countervail currency subsidies that harm U.S. industries," Commerce Secretary Wilbur Ross had said in a statement. "Foreign nations would no longer be able to use currency policies to the disadvantage of American workers and businesses," he said.