German Chancellor Angela Merkel said Sunday that President Trump's refusal to endorse a communique from the Group of Seven (G7) leaders was "sobering and a bit depressing."

Merkel made the remark during an interview with Germany's ARD television broadcaster following the conclusion of the summit in Quebec.

In the same interview, Merkel said the European Union was preparing to implement counter-measures against U.S. tariffs on imported steel and aluminum. Trump imposed tariffs of 25 percent on steel imports and 10 percent on imported aluminum from the EU on June 1, a move he said was meant to protect U.S. national security.

After leaving the summit Saturday, Trump announced that the U.S. was pulling back its endorsement of the G7 communique in part because of what he called "false statements" at a news conference by Canadian Prime Minister Justin Trudeau.

A few hours earlier, Trudeau had told reporters that all seven leaders had come together to sign the joint declaration.

Trump tweeted: "Based on Justin's false statements at his news conference, and the fact that Canada is charging massive Tariffs to our U.S. farmers, workers and companies, I have instructed our U.S. Reps not to endorse the Communique as we look at Tariffs on automobiles flooding the U.S. Market!"

Late Sunday, Trump tweeted from Singapore that "Fair Trade is now to be called Fool Trade if it is not Reciprocal."

"According to a Canada release, they make almost 100 Billion Dollars in Trade with U.S. (guess they were bragging and got caught!). Minimum is 17B. Tax Dairy from us at 270%. Then Justin acts hurt when called out!"

Meantime, French President Emmanuel Macron responded by saying international partnerships could not be "dictated by fits of anger and throwaway remarks," the BBC reported.

Trump had delivered a stark warning to America's trading partners not to counter his decision to impose tariffs on steel and aluminum imports. But the summit host, Trudeau, whose nation was among those singled out by Trump, pushed back and said he would not hesitate to retaliate against his neighbor to the south.

"If they retaliate, they're making a mistake," Trump declared before departing the annual Group of Seven summit, which includes Britain, Italy, France, Germany and Japan.

Trudeau later said he reiterated to Trump that tariffs will harm industries and workers on both sides of the U.S.-Canada border. He said unleashing retaliatory measures "is not something I relish doing" but that he wouldn't hesitate to do so because "I will always protect Canadian workers and Canadian interests."

"As Canadians, we are polite, we're reasonable, but also we will not be pushed around," Trudeau said.

Despite the sharp differences, Trudeau said all seven leaders had come together to sign a joint declaration despite having "some strong, firm conversations on trade, and specifically on American tariffs."

During a rare solo news conference earlier Saturday, Trump said he pressed for the G7 countries to eliminate all tariffs, trade barriers and subsidies in their trading practices. He reiterated his longstanding view that the U.S. has been taken advantage of in global trade, adding, "We're like the piggy bank that everybody's robbing, and that ends."

He said U.S. farmers had been harmed by tariffs and other barriers and warned that U.S. trading partners would need to provide him with more favorable terms: "It's going to stop or we'll stop trading with them."

Fox News' Mike Arroyo and The Associated Press contributed to this report.