Trump has leveled much of his criticism at the failure of more North Atlantic Treaty Organization members to spend 2 percent of gross domestic product on defense. The U.S.is at 3.5 percent, or $685 billion previous year.
"President Trump wants to see our allies share more of the burden, and at a very minimum meet their already stated obligations".
At present, the Liberal government's spending projections show Canada reaching only 1.4 per cent of GDP by 2024.
He said: "Why are their (sic) only 5 out of 29 countries that have met their commitment? We have a tremendous relationship with Germany", Mr Trump said.
"We have a very, very good relationship with the chancellor. So we're going to have a meeting on that", Trump said, describing the situation as "disproportionate and not fair to the taxpayers of the United States".
MARTIN: Meanwhile, President Trump gets ready for his summit with Vladimir Putin on Monday.
"Based on our agreed approach of doing nothing on Ukraine without Ukraine, I wish Mr Trump well in his efforts to bring Mr Putin back into line".
At the summit's opening, U.S. President Donald Trump railed against what he characterized as a "massive gas deal" between Germany and Russian Federation, calling it inappropriate.
He said nations have been increasing their contribution each year, even as they have taken a hit to their own economies by putting in place tough sanctions against Russian Federation for its behaviour in Ukraine. The pipeline is opposed by the United States and some EU members, including European Council President Donald Tusk.
German Chancellor Angela Merkel also responded Wednesday to Trump's remarks, offering Trump something of a history lesson.
"I myself experienced that a part of Germany that was controlled by the Soviet Union, and I am very happy today that we are united in freedom as the Federal Republic of Germany", Merkel told reporters, according to the Washington Post.
Any such increase would be almost impossible for smaller countries in Europe to achieve, and it is not clear that the capitals of Europe could muster the public or political support for such breathtaking increases in defense spending.
He claimed not enough money was being spent on defence, despite marked increases.
Trump didn't blame Stoltenberg for the state of affairs, however. Budget increases started after Russia's 2014 annexation of Ukraine's Crimean Peninsula, and they have accelerated in the Trump era in response to the US President's criticism.
"I welcome President Trump's forthcoming meeting with President Putin: open channels of communication between the USA and Russian Federation are key to managing the risks of confrontation", she planned to say, according to the spokesman.