BRUSSELS (CBSNewYork/AP) — President Donald Trump is in Brussels Wednesday for meetings with leaders of NATO countries where he made some controversial remarks about Germany’s relationship with Russia.

Trump claimed a pipeline project has made Germany “totally controlled” by and “captive to Russia” during a combative breakfast Wednesday that kicked off what was already expected to be a fraught NATO summit.

In a testy exchange with NATO Secretary General Jens Stoltenberg, Trump took issue with the U.S. protecting Germany when the European nation is making deals with Russia.

The president appeared to be referring to the Nord Stream 2 pipeline that would bring gas from Russia to Germany’s northeastern Baltic coast, bypassing Eastern European nations like Poland and Ukraine and doubling the amount of gas Russia can send directly to Germany. The vast undersea pipeline is opposed by the U.S. and some other EU members, who warn it could give Moscow greater leverage over Western Europe.

“Germany, as far as I’m concerned, is a captive of Russia because it’s getting so much of its energy from Russia,” said Trump. He also urged NATO to look into the issue.

German Chancellor Angela Merkel responded to Trump’s remarks as she arrived for the summit, telling reporters: “I have experienced myself how a part of Germany was controlled by the Soviet Union. I am very happy that today we are united in freedom, the Federal Republic of Germany. Because of that we can say that we can make our independent policies and make independent decisions. That is very good, especially for people in eastern Germany.”

Stoltenberg pushed back over breakfast, too, stressing that NATO members have been able to work together despite their differences.

Typically leaders hash out conflicts in private, but the tense exchange unfolded with cameras rolling. It left no question as to how hard the president intends to press America’s NATO allies over money.

Trump is expected to continue hammering jittery NATO allies about their military spending during the summit, which comes amid increasingly frayed relations between the “America first” president and the United States’ closest traditional allies.

Stoltenberg thanked the president earlier for pushing other countries to increase their defense spending.

So far this year, only five of 29 NATO countries, including the U.S., spent 2% of gross domestic product on defense, which is the NATO standard.

“Your message is having an impact,” Stoltenberg told Trump.

Next week Trump meets with Russian President Vladimir Putin in Finland.

Before that he’ll visit Great Britain for meetings with Prime Minister Theresa May and tea with Queen Elizabeth.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)