BRUSSELS (AP) — In a combative start to his NATO visit, President Donald Trump asserted Wednesday that a pipeline project has made Germany “totally controlled” by and “captive to Russia” and blasted NATO allies’ defense spending, opening what was expected to be a fraught summit with a list of grievances involving American allies.

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

“I have to say, I think it’s very sad when Germany makes a massive oil and gas deal with Russia where we’re supposed to be guarding against Russia,” Trump said during a breakfast with Stoltenberg, his first event since arriving in Brussels. “We’re supposed to protect you against Russia but they’re paying billions of dollars to Russia and I think that’s very inappropriate.”

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.

Trump said that, “Germany, as far as I’m concerned, is captive to Russia” and urged NATO to look into the issue. Trump, who has been accused of being too cozy with Putin — a man accused of U.S. election meddling — was expected to see German Chancellor Angela Merkel later in the day.

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

The dramatic exchange set the tone for what was already expected to be a tense day of meetings with leaders of the military alliance. Trump is expected to continue hammering jittery NATO allies about their military spending during the summit meeting, which comes amid increasingly frayed relations between the “America first” president and the United States’ closest traditional allies.

“The United States is paying far too much and other countries are not paying enough, especially some. So we’re going to have a meeting on that,” Trump said as he arrived at the breakfast, describing the situation as “disproportionate and not fair to the taxpayers of the United States and we’re going to make it fair.”

“They will spend more,” he later predicted. “I have great confidence they’ll be spending more.”

White House press secretary Sarah Huckabee Sanders announced hours after the exchange over Germany that Trump would meet later Wednesday with Merkel, as well as with French President Emmanuel Macron. Journalists will not be allowed to cover either meeting, she said.

Trump has been pushing NATO members to reach their agreed-to target of spending 2 percent of their gross domestic products on national defense by 2024 and has accused those who don’t of freeloading off the U.S.

“Many countries in NATO, which we are expected to defend, are not only short of their current commitment of 2% (which is low), but are also delinquent for many years in payments that have not been made,” he tweeted Tuesday while en route to Europe, asking: “Will they reimburse the U.S.?”

That’s not how the spending words. The 2 percent represents the amount each country aims to spend on its own defense, not some kind of direct payment to NATO or the U.S.

NATO estimates that 15 members, or just over half, will meet the benchmark by 2024 based on current trends.

During his campaign, Trump called NATO “obsolete” and suggested the U.S. might not come to the defense of members if they found themselves under attack — a shift that would represent a fundamental realignment of the modern world order. He also called Brussels a “hell hole” and “a mess.” Trump has moderated his language somewhat since taking office, but has continued to dwell on the issue, even as many NATO members have agreed to up their spending.

Stoltenberg, for his part, credited Trump for spurring NATO nations to spend more on defense, noting that the Europeans and Canada are projected to spend around $266 billion more by 2024.

“We all agree that we have to do more,” he said, describing last year as marking the biggest increase in defense spending across Europe and Canada in a generation.

Trump interjected, asking Stoltenberg why he thought that had happened.

“It’s also because of your leadership, because your clear message,” Stoltenberg responded.

Trump took credit for the spending, telling the NATO chief that “because of me they’ve raised about $40 billion over the last year. So I think the secretary general likes Trump. He may be the only one, but that’s OK with me.”

Trump was also participating in a welcome ceremony, a meeting of the North Atlantic Council and a working dinner with some of the same leaders he berated over trade during his last world leaders summit in Canada last month.

Brussels is the first stop of a weeklong European tour that will include stops in London and Scotland, as well as a highly anticipated meeting next week with Russia’s Vladimir Putin.

Trump predicted as he departed Washington that the “easiest” leg of his journey would be his scheduled sit-down Putin — a comment that did little to reassure allies fretting over his potential embrace of a Russian leader U.S. intelligence officials accuse of meddling in the 2016 elections to help Trump win.

On the eve of the NATO summit, European Council President Donald Tusk pushed back against Trump’s constant criticism of European allies and urged him to remember who his friends are when he meets with Putin in Helsinki.

“Dear America, appreciate your allies, after all you don’t have all that many,” he said.