He told fellow leaders he would prefer a 4 percent target, closer to the 3.6 percent of GDP the United States spends on defense. While Germany's spending is increasing, it will not reach the target by 2024, instead expecting to boost spending to 1.5 percent by 2025.
Canada only contributed 1.29% of its GDP, while Germany - which has drawn criticism from President Trump - spent 1.24% of its GDP on defense a year ago.
The comments received a swift and sharp rebuke from German Chancellor Angela Merkel.
In March, Germany agreed to allow Russia's energy-exporting monopoly Gazprom to build a pipeline through its waters.
"I am pleased to have this opportunity to be here for this exchange of views", she said, through a translator.
Trump kept going, saying previous American leaders have mentioned the 2 percent issue but either did not understand like he does or "didn't want to get involved". Also present was France's President Emmanuel Macron, who tried this year to charm Mr Trump into more harmonious transatlantic relationship, only to see the USA president withdraw from the 2015 Iranian nuclear deal and impose tariffs on European goods.
Ex-UCLA basketball player found dead in Phoenix, posted farewell video
Knight was a fantastic player for the Bruins between 1997 and 2002, but unfortunately is yet another UCLA alum gone too soon. He wasn't picked in the 2002 National Basketball Association draft but played professionally in France and Japan.
Trump admitted that the issue came up during his meeting with Merkel. But after a day of Trump throwing political hand grenades at Germany, he and Merkel gave a cool and cordial read out of their private meeting.
"I think we meet with our adversaries". "We have a tremendous relationship with Germany".
"I believe that our trade will increase and lots of other things will increase, but we'll see what happens".
"Germany is totally controlled by Russia", Trump said, contending the European country gets up to 70 percent of its energy from the Russian pipeline.
It's been - to say the least - an uneasy day thus far at the North Atlantic Treaty Organisation summit in Brussels between President Donald Trump and German Chancellor Angela Merkel.
After Trump's cordial reception of Merkel in the afternoon, it seemed Trump avoided the kind of diplomatic disaster he set in motion at the G7 in June.
Diplomats were already anxious about the summit ahead of time, not least because of an abrasive G7 meeting last month, when Mr Trump renounced a summit communique that had previously been jointly agreed.
John Kelly, Mr Trump's chief of staff, and Mike Pompeo, his secretary of state, sat silently alongside Mr Trump as he delivered the criticism across the table to Mr Stoltenberg.