BERLIN -- German Chancellor Angela Merkel, who has been a key U.S. ally in the past, but has disagreed with Trump positions, was sworn in Wednesday for her fourth term leading the world’s fourth-largest economy.

In a campaign rally in July, Chancellor Merkel clearly laid out her position towards some of Trump's policies, saying that Germany "could no longer rely on the U.S. to some extent."

Over her time as leader, the Germany-U.S. relationship has changed. The two countries had developed a stronger partnership during the terms of former President Obama, with whom Merkel was said to have a close relationship.

Obama had said that Merkel was likely his "closest international partner." Merkel said at his last presidential visit to Germany that "the parting is hard for me."

Merkel enters her new term with a possible trade war looming. Based on her past, many believe she is unlikely to concede easily to the conditions Trump has laid out on trade tariffs, which could have devastating consequences on the German economy.

The chancellor is expected to push back and collaborate with the European Union, according to senior transatlantic fellow at the German Marshall Fund of the United States, Sudha David-Wilp.

"Trade is something that is important to the EU, and they will work together to make sure the the U.S. realizes the EU won’t take this lying down," she told ABC News.

"From once being the sought-after indispensable partner, Germany is now kind of left in the cold and feeling threatened by the U.S.," she adds. "It’s definitely a different time than it was two years ago."

During the last U.S. presidential elections, she refrained from sharing any thoughts about Donald Trump, but set clear terms for continuing German support in a statement congratulating him on his victory.

At the time, Merkel said that close cooperation would be offered on the basis of continued shared values, such as "democracy, freedom, the respect for the law and the dignity of human beings, independent of their origin, skin color, religion, gender, sexual orientation or political position."

While not exactly the fire and fury language often used in U.S. politics, many in Germany saw the statement as a lecture on core Western values and a strong rebuke for an incoming U.S. president.