During Angela Merkel's visit to the White House Friday, President Trump refused to shake the German chancellor's hand in front of a crowd of cameras.
Trump has also anxious United States allies by criticising the military alliance as "obsolete" and failing to meet the challenge posed by Islamic terror groups.
Trump shares a different opinion when it comes to immigrants and past year, during his presidential campaign, the US President had taken pot shots at Merkel of allowing refugees from Syria to take shelter in Germany.
The polar opposites met in Washington for the first time since Trump assumed office in January, and the face-to-face was sure to be filled with its share of tense exchanges behind closed doors.
During a photo op in the Oval Office, the two did not shake hands before reporters. "We will have a different policy but it's going to be a great policy for the United States [and] a great policy worldwide".
Asked if he ever tweets things he regrets, Trump replied, "Very seldom".
Prior to his inauguration, Trump declared North Atlantic Treaty Organisation "obsolete" but has since modified his stance, telling European leaders the alliance remains of strategic importance.
The discussions on trade did not take off and the two leaders will sit down again for this. Trump also thanked Merkel for her commitment to increase spending and work towards the two percent figure that every nation under North Atlantic Treaty Organisation, including Germany, is required to spend on defence.
Merkel, whose visit with her new USA counterpart was marked by cool distance in their public appearances, was left to explain that trade negotiations are the province of the European Union, not her government, and that there are no such German interlocutors. He said: "I don't believe in isolationist policy, but I also believe that a trade policy should be fair".
After Trump suggested they shared the experience of being covertly monitored by the previous government, the German chancellor couldn't hide her surprise, narrowing her eyes and wincing before staring at the president with barely disguised astonishment. Trump, however, said little about ongoing trade negotiations between the United States and the European Union, even as Merkel expressed optimism that the US and EU could hammer out an agreement where "both sides win".
Mrs Merkel responded by saying the European Union had to take responsibility for itself.
In response, Merkel said it was important to stop traffickers but it must be done with the aim of giving refugees the chance to lead better lives.
"We were trying to address the areas we disagree", she said of their ideological opposition.
The talks aimed to represent a restart of a relationship complicated by Mr Trump's rhetoric on the campaign trail.