"The pipeline gets cheap Russian gas to Germany while bypassing smaller Eastern European nations, allowing Russia to pressure them while Germany is held harmless", he tweeted, adding: "No amount of preening in Berlin will cover this nakedly selfish policy".
Trump also said it was "very inappropriate" that the United States was paying far more to defend Europe than other members of North Atlantic Treaty Organisation, repeating a constant complaint raised in recent days in both spoken comments and on Twitter.
He added that "Germany is totally controlled by Russian Federation".
The U.S. president's tirade was about it not being "fair to American taxpayers that Germany buys oil and gas from Russian Federation while enjoying the umbrella of defense provided by U.S. dollars", reports NBC News.
While NATO members increased overall defense spending in 2017, for a second consecutive year, the United States was still largely outspending all other members.
"I think it's very unfair to our country", Trump said. "But other presidents never did anything about it because I don't think they'd up it or wanted to get involved", Trump said.
"When Germany makes a massive oil and gas deal with Russia", Trump said to Stoltenberg.
The document reportedly emphasizes the importance of maintaining a dialogue between the Russian and USA heads of state, diplomats, militaries, and intelligence agencies, and calls for closer economic ties and more contact between Russians and Americans.
"I think these countries have to step it up, not over a 10 year period, they have to step it up immediately".
Pressed by Trump, Stoltenberg said the president's frequent criticism was having an impact, encouraging countries to spend more.
"How can you make that point with the little evidence that you have and the fact that there is no alternative planning on the table?" she said.
Trump's words about the upcoming Putin meeting contrasted sharply with the way in which he assailed Germany as he arrived in Brussels.
Trump said: "We're protecting Germany, we're protecting France, we're protecting all of these countries". "After the attacks of 9/11, we called on Germany's leadership to fight with us in Afghanistan". German Chancellor Angela Merkel has said that the project is a private commercial venture, not funded by German taxpayers, Reuters reported. "We're protecting everybody. this has been going on for decades", Trump said.
"Germany is captive of Russian Federation because it is getting so much of its energy from Russian Federation. I am very happy that we are today united in freedom as the federal republic".