Trump's comments drew forceful pushback from the typically staid NATO Secretary General Jens Stoltenberg, who went back and forth with Trump over the importance of preserving the alliance.
"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.
Foreign Affairs Minister Chrystia Freeland says Canada has significant concerns over the Nord Stream 2 pipeline that would bring gas from Russian Federation to the Baltic coast of Germany.
President Trump on Wednesday stoked divisions in Europe by wading into the middle of an intense fight over the Nord Stream 2 natural gas pipeline, a project that critics fear will give Moscow new leverage in the region and could create a geopolitically unsafe Russian-German economic alliance.
Trump's pipeline criticism was an unusual line of attack for a president who has appeared eager to improve relations with Putin and dismissed the US intelligence community's assessment that Russian Federation tried to undermine Western democracy by meddling in the 2016 USA presidential election to help Trump win.
Stoltenberg acknowledged that Trump had expressed himself in "very direct language" but insisted that away from the fiery rhetoric the allies all agree on fundamental issues: the need to boost NATO's resilience, fight terror and share the cost of defence more equally.
Republican Sen. Orrin Hatch also took issue with Trump, saying "I don't agree with that".
"Dear America, appreciate your allies", Tusk said on Tuesday.
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.
The president is expected to meet with the leaders of Azerbaijan, Romania, Ukraine and Georgia before he travels to London Thursday.
In a tweet posted before his departure, Mr Trump put European allies on notice that he will be taking a tough stance on their contributions to the military alliance, as well as barriers to USA trade. "We are talking about trade, we have a very, very good relationship with the chancellor, we have a tremendous relationship with Germany", Trump said with Merkel sitting at his side. In a tweet Tuesday, he said: "Will they reimburse the USA?"
"We have a very, very good relationship with the chancellor".
"Putin is emboldened pretty much with or without Trump".
In addition to the president, other USA officials have taken to the world stage this week to decry the project. "They just did it more politely", Elisabeth Braw, adjunct fellow from the Center for European Policy Analysis, told CNN. I mean, don't forget, many countries went to Iraq and Afghanistan and many, many soldiers were killed from all these countries, and it was not their war, it was an American war really, more than anything else.
That's not how the spending works. NATO, the 70-year-old intergovernmental military alliance that's devoted to collective global security, has come under attack from Trump. He also called Brussels a "hell hole" and "a mess".
"The idea is that every country should have strong armed forces on its own, so that North Atlantic Treaty Organisation really just is for common defense - it shouldn't be that there are free riders who spend nearly nothing but say, 'I'm a member of an alliance'".
Many Eastern European officials fear the undersea method could allow a hostile Moscow to shut off fuel shipments to perceived enemies such as Ukraine, for example, while still getting the fuel to Germany, which upon completion of the project would become the continent's No. 1 natural gas hub.
"I think these countries have to step it up, not over a 10 year period, they have to step it up immediately". Sestanovich shared a joke going around the Pentagon that Trump is tweaking Mattis' "Mad Dog" nickname and now calls the secretary "Moderate Dog Mattis". "He may be the only one, but that's OK with me".
Trump predicted as he departed Washington that the "easiest" leg of the journey would be the sit-down with Putin - a comment that did little to reassure allies fretting over his potential embrace of a Russian leader they regard as hostile.
Even if Trump does not make specific threats while in Brussels, some experts argue that the appearance of discord among the allies could undermine the alliance in ways that benefit Moscow.