BRUSSELS (Reuters) -The European Commission said on Saturday that it "strongly" regrets an announced increase of U.S. tariffs on steel imports and that the EU is prepared to impose countermeasures.

U.S. President Donald Trump said on Friday he planned to increase tariffs on imported steel and aluminum to 50% from 25%, putting more pressure on global steel producers and deepening his trade war.

"We strongly regret the announced increase of U.S. tariffs on steel imports from 25% to 50%," a European Commission spokesperson said in an emailed statement.

"This decision adds further uncertainty to the global economy and increases costs for consumers and businesses on both sides of the Atlantic," the spokesperson said, adding that "the tariff increase also undermines ongoing efforts to reach a negotiated solution".

The spokesperson noted that the European Union had paused its countermeasures to create space for continued negotiations.

"The EU is prepared to impose countermeasures, including in response to the latest U.S. tariff increase," the spokesperson said.

"The European Commission is currently finalising consultations on expanded countermeasures. If no mutually acceptable solution is reached, both existing and additional EU measures will automatically take effect on 14 July - or earlier, if circumstances require," they added.