'We are protecting Germany, we are protecting France, we are protecting all of these countries and then numerous of the countries go out and make a pipeline deal with Russian Federation where they are paying billions of dollars into the coffers of Russian Federation.
Germany is extremely reliant on Russian gas, and the new Nord Stream 2 pipeline in the Baltic Sea, which Germany approved in March, will only increase its dependence.
Trump then heads to Helsinki to meet Putin.
Mr Trump said as he arrived at the breakfast that the situation was "not fair to the taxpayers of the United States but we will make it fair".
Trump alarmed allies during a visit to Brussels a year ago when he did not specifically mention USA backing for Article 5, but aides said later that United States support was assumed and did not have to be mentioned.More news: Serena Williams into Wimbledon semi-finals with win over Camila Giorgi
"European allies are stepping up", NATO Secretary General Jens Stoltenberg told reporters on Tuesday in Brussels.
"So we're supposed to protect Germany but they're getting their energy from Russian Federation".
Some NATO members point out that only 15% of America's defence spending goes on defending Europe, and that the emphasis should be on adapting NATO for new threats, not simply spending more money on defence.
"After all, you don't have that many", the former Polish prime minister said in a rebuke of Mr. Trump's criticism of North Atlantic Treaty Organisation nations who are not meeting their defense spending obligations.
Past year saw the biggest increase in defence spending in a generation, he said.
May's relationship with Putin is frosty - the United Kingdom believes the Kremlin was behind the order to poison former spy Sergei Skripal in western England with a nerve agent - and the one with Trump could be better.
The 29 allies are due to restate a commitment to try to spend two percent of GDP on defense by 2024, according to excerpts of their final summit declaration seen by AFP. Very supportive. And maybe we'll speak to him when I get over there.More news: Pogba urges France to avenge Euros defeat
Washington and some European Union countries oppose the project, warning that it could give Moscow greater leverage over Western Europe. 'I think its a very bad thing for NATO, ' Trump said. For years, countries like Germany, Spain, Italy, Canada, and others have not even come close to meeting their obligations to the collective defense alliance.
"I look forward to having words with President Trump".
But Germany, Europe's biggest economy, spends just 1.24 percent of GDP on defence, compared with 3.5 percent for the US. "We're not going to put up with it, we cant put up with it", he said.
Despite Russia's aggressive moves in Ukraine and confirmed election meddling in the USA, the president wouldn't say if Putin was friend or foe.
European Council President Donald Tusk said on Tuesday in a message to Trump that "it is always worth knowing who is your strategic friend and who is your strategic problem". Frankly, Putin may be the easiest of them all.
The NATO summit is also being attended by leaders of so-called NATO partner states that are not members of the alliance.More news: China's Nobel winner's widow Liu Xia leaves Beijing for Germany
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