WASHINGTON () President Donald Trump challenged U.S. allies Wednesday by increasing tariffs on all steel and aluminum imports to 25% as he vowed to take back wealth “stolen” by other countries, drawing quick retaliation from Europe and Canada.

The Republican president’s use of tariffs to extract concessions from other nations points toward a possibly destructive trade war and a stark change in America’s approach to global leadership. It also has destabilized the stock market and stoked anxiety about an economic downturn.

“The United States of America is going to take back a lot of what was stolen from it by other countries and, frankly, by incompetent U.S. leadership,” Trump told reporters Wednesday. “We’re going to take back our wealth, and we’re going to take back a lot of the companies that left.”

Trump removed all exemptions from his 2018 tariffs on the metals in addition to increasing the tariffs on aluminum from 10%. His moves, based on a February directive, are part of a broader effort to disrupt and transform global commerce.

He has separate tariffs on Canada, Mexico and China, with plans to also tax imports from the European Union, Brazil and South Korea by charging “reciprocal” rates starting April 2.

The EU announced its own countermeasures Wednesday. European Commission President Ursula von der Leyen said that as the United States was “applying tariffs worth 28 billion dollars, we are responding with countermeasures worth 26 billion euros,” or about $28 billion. Those measures, which cover not just steel and aluminum products but also textiles, home appliances and agricultural goods, are due to take effect April 1.

Meanwhile, Vice President JD Vance says the administration believes it is in a “very good place” as it pushes the Kremlin to sign off on a U.S.-backed proposal to pause the fighting with Ukraine for 30 days.

He says U.S. officials will have conversations with their Russian counterparts by phone and in person in the coming days.

Trump says he has received some good feedback on the proposal. He has offered no details.

“I’ve gotten some positive messages, but a positive message means nothing. This is a very serious situation,” Trump said. “This is a situation that could lead to World War III.”

“We’ve gotten half of it as a ceasefire,” Trump added. “And if we can get Russia to stop, then we have a full ceasefire. And I think it’ll never go back to war.”

The Associated Press contributed to this report.