He earlier accused Germany of being held prisoner to imported Russian energy, claiming it is "totally controlled" by Moscow.
Ahead of the Helsinki summit later this month, Putin also commented about the souring relationship with the U.S.
Trump complimented Stoltenberg, saying "he's worked very hard on this problem". "But other presidents never did anything about it because I don't think they'd up it or wanted to get involved", Trump said.
Former Secretary of State John Kerry condemned President Donald Trump's remarks at the NATO Summit Wednesday morning after the president bashed Germany saying the country is being "controlled" by Russian Federation. On top of that Germany is just paying just a little bit over 1% whereas the United States is paying 4.2% of a much larger GDP.
He described the current situation as "disproportionate and not fair to the taxpayers of the United States".
"They will spend more", he later predicted.
"Because of me they've raised about $40 billion over the past year".
And with that, he went on to push allies at the summit to double their commitment on defence spending.
However, Trump at the summit told North Atlantic Treaty Organisation leaders they should increase their defense spending to 4 percent of their country's GDP (gross domestic product), higher than NATO's goal of 2 percent, a White House official said on Wednesday.
Ms. Merkel has been considerably tougher on Russian President Vladimir Putin than Mr. Trump has; unlike the USA president, she has never suggested acceptance of Russia's forcible annexation of Crimea.
US President Donald Trump pauses while speaking to members of the media on July 10.
President Donald Trump on Wednesday launched a broadside against Germany in which he highlighted a growing connection between the two countries.
"We have had discussions, we do have disagreements, but most importantly we have decisions that are pushing this alliance forward and making us stronger". "We have a tremendous relationship with Germany", he said. Germans wouldn't agree with that. He added the USA and Germany have a good relationship.
If Mr. Trump's real concern were inadequate European spending, he should have started by better informing himself.
"We're protecting everybody, and yet we're paying a lot of money to protect", Trump said. In a tweet Tuesday, he said: "Will they reimburse the USA?"
But Merkel nevertheless insisted Washington and Berlin remain allies, saying: "We are partners, we are good partners and wish to continue to cooperate in the future". But the two appeared on good terms, with Trump joking about the fact that Macron had been asked about it. "Why are there only 5 out of 29 countries that have met their commitment?" "And then numerous of the countries go out and make a pipeline deal with Russian Federation where they're paying billions of dollars into the coffers of Russian Federation", he said. "Must pay 2% of GDP IMMEDIATELY, not by 2025".