"It was a little tough for a little while".
He complained the United States "pays tens of Billions of Dollars too much to subsidize Europe" and demanded that member nations reach their goal to spend 2 per cent of GDP on defence, which "must ultimately go to 4%!"
Though she said that Germany did have "a lot of issues with Russian Federation", she noted that it was important to "keep the communication line between countries or alliances and opponents" open.
Others say Congressional approval would be required - and would be unlikely to be forthcoming.
German Chancellor Merkel hit back immediately, not only denying Trump's contention but suggesting that his comfortable upbringing in the US gave him no standing to spout off on the world stage about Germany.
Several diplomats and officials said, however, that his undiplomatic intervention - including pointing at other leaders and addressing Merkel as "you, Angela" - had irritated many.
Trump has repeatedly slammed Merkel for supporting a new pipeline that would cement Berlin's client relationship with Russian Federation and increase Moscow's influence.
U.S. President Donald Trump, left, and German Chancellor Angela Merkel pose for a photograph prior to a bilateral meeting on the eve of the G-20 summit in Hamburg, northern Germany, Thursday, July 6, 2017.
The first is that member states spend 2 percent of their annual gross domestic product on the military.
But he said that since past year around an additional 33 billion dollars, not including the United States, had been raised and it was now "unnecessary" to withdraw from the organisation. "I don't know that is what they voted for".
As has been noted many times since Trump started making assertions about underpayment on the campaign trail in 2016, his representation of how the system works is not accurate.
Another diplomatic source said that a "special session on burden sharing is ongoing". "I made clear that we are on this path".
He said North Atlantic Treaty Organisation chief Jens Stoltenberg had given "total credit" to him for the increased spending, which he said he instigated during his first North Atlantic Treaty Organisation meeting past year. (It's one of three countries to have passed a law mandating an increase to 2 percent.) Since Trump began advocating for countries to hit that goal, 16 have increased spending relative to GDP by at least 5 percent; six of those countries had already increased by at least 5 percent during the two prior years as well.
"The commitment was at two percent and that'll be going up quite a bit higher than that", he said.
Spanish Prime Minister Pedro Sanchez, who like the summit host, Belgian Prime Minister Charles Michel, was singled out in the room by Trump for spending less that 1 percent of GDP on defence, said Madrid would also meet the target by 2024. "Secretary Stoltenberg gives us total credit, meaning me, I guess, in this case, total credit".
'I think that a lot of the people in the United Kingdom - I think that's why Brexit happened, ' Trump said.