The Chancellor acknowledged that climate change talks at the G20 would not be easy.
"We want to tackle this existential challenge and we can't and we won't wait until the last person on earth is convinced of the scientific basis for climate change", Merkel said.
The Trump administration's "America First" approach to trade has caused widespread concern internationally, as has its decision to pull out of the Paris accord.
"The discord is obvious and it would be dishonest to paper over the conflict", she said. "I won't do that, in any case". The presidents of the European Council and the European Commission will also participate in the meeting.
German Chancellor Angela Merkel said Thursday that she was considering how to protect "strategic" European Union industries from Chinese investment, drawing closer to the position of French President Emmanuel Macron.
Trump Twitter: Obama 'colluded or obstructed' trying to help Clinton
On Sunday, he lambasted Obama in a "Fox & Friends" interview for doing "nothing" about the election meddling. It's a long, long story that is of interest from a variety of perspectives.
Trump withdrew the USA from the agreement at the start of June.
Germany is a key United States trading partner and ally in Europe, but relations have grown more tense since Trump came into office.
A short while later, Trump announced he was pulling the United States out of a landmark agreement to combat climate change agreed in 2015 in Paris.
But he said Europe would "clearly reaffirm our very strong commitment to the Paris accords", adding: "I hope that the others can be brought back to their senses".
"Only by working together can we overcome these problems".
Houston Rockets: James Harden Did Not Win the MVP
He was the obvious best example of instant offense off anyone's bench, averaging 16.2 for the high-powered, high-octane Rockets. Durant forgot to congratulate Sixth Man of the Year victor Eric Gordon , so he jumped back in with a follow-up comment .
"That was the USA secretary of commerce, who had promised us a 10-minute statement", the head of CDU Economic Council Werner Bahlsen said.
Speaking at a joint news conference after a meeting, German Chancellor Angela Merkel stressed European participants in the G20 were committed to the Paris climate accord.
"We deplore, at least I say that for Germany, that the United States of America has chose to leave this agreement", Merkel told reporters.
Later, though, Merkel brushed off a question about chances of G-20 members except Trump drawing up a statement on climate change.
Germany is considering whether some industrial sectors should be designated as being of strategic importance to Europe, Chancellor Angela Merkel said, adding that there was a risk of companies becoming over-dependent on the emerging giant.
Biggest Blaze in the US: Utah Battling Nation's Largest Active Wildfire
A fire sparked by a traffic collision in California's Placerita Canyon is the latest blaze to hit the West amid a deadly heatwave. Wildfires continue to tear through parts of the western USA , and the region's dry conditions are literally fanning the flames.