Donald Trump Angela Merkel
Germany's Chancellor Angela Merkel and US President Donald TrumpReuters

German Chancellor Angela Merkel on Thursday promised to fight for free trade and continue to push efforts to combat climate change at the upcoming G20 summit next. Merkel's statements challenged the United States President Donald Trump's "America First" policies.

The European leader gave a defiant speech at the parliament just a week before the summit which will see the world's top economic powers gathered in Hamburg. Although Merkel did not take the US President's name, she clearly said global problems can not be solved through isolation and protectionism-- a dig at Trump's policies.

Soon after her speech, Merkel met with the European G20 leaders who assured her to present a united front in Hamburg. However, the leaders stated they preferred compromise than conflict.

"These will not be easy talks," Merkel said. "The differences are obvious and it would be wrong to pretend they aren't there. I simply won't do this."

Trump appears to refuse handshake with Angela Merkel
German Chancellor Angela Merkel and Donald Trump

The G7 summit held in Sicily in May had exposed deep divisions between western countries and Donald Trump over issues of trade, immigration and climate change. Shortly after the meeting, Trump announced the US was pulling out of the global climate accord.

Merkel's latest statements increase the prospect of a clash with Trump and the world leaders at the upcoming summit.

Trump administration, ahead of the G20 summit, has also threatened to take punitive trade measures against China, including introducing tariffs on steel imports, according to Reuters.

When asked about the German Chancellor's comments, Trump's national security adviser, HR McMaster said the US' ties with Germany are "as strong as ever."

"Of course there are going to be differences in relations with any country, and we'll talk frankly about those differences. The president enjoys those conversations," McMaster said.