Washington repeated a warning on Wednesday to Western firms invested in Russia's Nord Stream 2 pipeline to Germany that they were at risk of sanctions, and said Moscow was using the project to divide Europe.
Mr. Trump also criticized Germany for failing to spend the agreed upon 2 percent of GDP on North Atlantic Treaty Organisation defense.
"We should first get to 2 pct", NATO Secretary-General Jens Stoltenberg, adding that eight of the 29 allies were meeting that target, while others had a plan to do - turning a leaf on years of defense budget cuts. "On top of that, Germany is just paying a little bit over 1 percent [on defense]... and I think that is inappropriate also", Trump said.
Mr Trump has repeatedly complained that the U.S. is left to provide the lion's share of funding for trans-Atlantic defence, as European states fail to meet Nato's target of spending 2% of GDP on the military.
"I'm very glad that today we are united in freedom. because of that we can say that we can make our independent policies and make independent decisions".
The president's critics have accused him of ignoring USA barriers to foreign products, and of seeking a tariff-fueled trade war with the Europeans (and the Chinese) that will undermine economies worldwide.
The Brussels meeting comes less than a week before Mr Trump is due to hold his first summit with Vladimir Putin, in Helsinki, reviving concerns among United States allies over his proximity to the Russian president.
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Del Potro was straining to stay in touch in almost every point, and his gambling instincts drove him to explore the white lines. There was a look of glee in Del Potro's sometimes sad eyes, and his lumbering between-points walk had a bit more energy to it.
The NATO alliance consists of 29 countries from North America and Europe, including the USA and Germany, which was originally set up in 1949 to thwart Soviet aggression in Western Europe.
US President Donald Trump shakes hands with Russian President Vladimir Putin during the their bilateral meeting at the G20 summit in Hamburg, Germany, July 7, 2017.
Trump will meet the Russian leader in Helsinki on 16 July for their first summit amid an ongoing investigation in the USA into possible Trump campaign collusion with Russia.
Mr Trump said: "The US is spending many times more than any other country in order to protect them".
The president singled out Germany's energy deal with Russian Federation.
"We call upon [North Korea] to fully implement its worldwide obligations; to eliminate its nuclear, chemical, and biological warfare capabilities and ballistic missiles, and abandon all related programmes", the statement said. But at the bilateral meeting he exulted: "We have a very, very good relationship with the Chancellor".
Mr Trump is the 12th sitting USA president to make such a trip, and will spend time with the Queen and prime minister before flying to Scotland to spend the weekend at his golf resort. "Enough. This isn't good for the United States and there are people across the aisle - as the Senate vote clearly showed - who know it and need to say it", Kerry wrote.
The defense minister agreed with Trump about defense spending.