Earlier in the day, Canadian PresidentJustin Trudeau said that they would move forward with "retaliatory measures".
If you weren't in the loop, the G7 Summit happened and there was a bit of turbulence.
Merkel, French President Emmanuel Macron and the other leaders clashed with Trump over steel and aluminum tariffs as well as his decision to abandon a deal with Iran to limit its nuclear program.
Many saw a distillation of a crisis of the West in the photograph, and a revival of the debate launched by U.S. and British media after Trump's 2016 election whether Merkel was the new "leader of the free world".
Macron said it was possible to make progress on the trade issues that have split the US and its allies after meeting with Trump.
Mr Trump's strained relationship with the rest of the G7 was in evidence on Saturday when he arrived late for the opening session, with Mr Trudeau addressing a gathering that included an empty chair where the president was meant to be.
"We finished the meeting, really, everybody was happy, and I agreed to sign something", Trump told reporters at a news conference following his summit with Kim Jong-un in Singapore.
Mr. Trump said that American farmers and workers have been hurt, with companies moving overseas to Mexico and Canada.
The G-7 has never been a tariff-free bloc, with member countries trading among one another under various agreements.
The US has slapped a 25% tariff on imports of steel and 10% on aluminium from countries including the United Kingdom and the rest of the European Union. "Sometimes I get the impression that the USA president believes that only one side wins and the other loses".
Already at the meeting of the finance ministers ahead of the G-7, the six non-U.S. countries released a statement raising concerns about US trade actions. Russian Federation was thrown out of what was then the G8 after it invaded and annexed Crimea - a strategic Black Sea peninsula - from Kyiv in 2014 and later fomented an ongoing war in Ukraine's eastern Donbass region that has killed almost 11,000 people.
There were also sharp words exchanged with French President Emmanuel Macron ahead of the summit, with Mr. Macron saying at a Thursday news conference in Ottawa with Mr. Trudeau that the U.S.'s metals tariffs against the European Union and Canada are pushing the six remaining nations of the G-7 to become a force of their own.
"Fair Trade is now to be called Fool Trade if it is not Reciprocal", Trump wrote in a series of posts on Twitter. Leaders expressed full support for seeking complete, irreversible, verifiable denuclearization, the official said.