German Chancellor Angela Merkel and US President Donald Trump were at odds on Iran, trade, NATO and many other issues. But their differences seemed to run deeper — and even be personal: Trump is said to have called Merkel "stupid." During talks at a NATO summit in late 2019, the pair seemed to be staring each other down.

The picture raised eyebrows around the world: Merkel and Trump at the G7 summit in Canada in June 2018. Is Merkel in control here, standing above Trump, as the true leader of the free world? Or is he the boss — the only one sitting? The image was released by the German government, captioned as a "spontaneous meeting between two working sessions."

President Trump appeared standoffish when he hosted Chancellor Merkel at the White House in March 2017. While in the Oval Office, the US president refused to extend a hand to the chancellor in front of media, a stiff image that defined their first encounter.

Merkel's bond with Barack Obama stood in sharp contrast to her relationship with Trump. The chancellor and Obama seemed to have become friends over the course of his two terms as US president. This picture was taken in November 2016, when Obama came to Berlin for a farewell visit — just a few days after Donald Trump was elected as his successor.

Merkel received the Presidential Medal of Freedom, the United States' highest civilian award, at the White House in June 2011. Obama praised her commitment to European unity. Observers also saw the award as proof of good German-American relations.

At the G7 summit in the Bavarian Alps in 2015, Merkel and Obama got along well. The chancellor was able to count on US support on many topics, such as in the fight against climate change. This ended abruptly when Trump became president in 2016.

Obama's predecessor, George W. Bush, made enthusiastic remarks about Merkel's love of freedom right after their first meeting. At the G8 summit in St. Petersburg in July 2006, he gave her an impromptu neck massage that took the chancellor by surprise. Still, it didn't seem to have put a strain on their relationship.

In July 2006, Bush enjoyed putting a piece of grilled wild boar on Merkel's plate. Merkel had welcomed him to her constituency on the coast of the northeastern German state of Mecklenburg-Western Pomerania. The barbecue was the highlight of the visit to Merkel's political home base.

In 2007 Merkel visited Bush at his ranch in Texas. Bush personally chauffeured Merkel and her husband, Joachim Sauer, in his American-made pickup truck. Merkel and Bush agreed to work together to find a diplomatic solution to the rising tensions over Iran's nuclear program.

At the funeral service for former German Chancellor Helmut Kohl in July 2017, former President Bill Clinton delivered a funny and emotional eulogy. "I loved him," he said. When he sat down again, he reached for Merkel's hand.

November 2009: Merkel has just delivered a speech before the US Congress in Washington, DC. While the applause went on, then-Vice President Joe Biden entertained the chancellor, making her laugh. Hopes are high for the German-American friendship now Biden has been elected president.