Trump asserted earlier Wednesday that Germany is "totally controlled" by and "captive to Russia" because of a pipeline project.
German Defense Minister Ursula von der Leyen dismissed Trump's comments, saying Germany is not captive to Russian Federation and the country can take Trump's criticisms in stride. The project is opposed by the USA and some European Union members.
"I will focus on what we have agreed and we have agreed that we committed to the pledge increasing defense spending to 2 percent", he told reporters.
Bob Menendez of New Jersey said Wednesday that he is "worried how the President will unfold" during the upcoming summit between President Donald Trump and Russian President Vladimir Putin in Helsinki.
Striking a strident tone at the summit, Trump's aspirational target of 4 percent of gross domestic product (GDP) was above the United States own spending on defense. "This has been going on for decades, for decades, it's disproportionate and not fair to the taxpayers of the United States".
"I have great confidence they'll be spending more", he said.
And with that, he went on to push allies at the summit to double their commitment on defence spending.
In a tweet today after a day of meetings, in which he lashed out at allies for insufficient defense spending, Trump calls on member nations to immediately boost spending. I think that is very inappropriate.
President Trump criticized trade agreements with other nations Wednesday morning, as he attends North Atlantic Treaty Organisation meetings.
Trump's harsh words for Merkel, whose country has hosted tens of thousands of US troops that have been key to post-WWII stability in Europe for seven decades, struck at the core of the alliance. Germans wouldn't agree with that. Because of me, they've raised about $40bn over the past year.
"Russia continues to say they had nothing to do with Meddling in our Election!", he tweeted last month before tearing into the Federal Bureau of Investigation and its former director James Comey.
The comments received a swift and sharp rebuke from German Chancellor Angela Merkel. Germany's leadership has said the pipeline is a private business decision and they have been reluctant to interfere.
Trump said on Tuesday that out of several meetings he will attend overseas in the coming weeks, the summit with Putin "may be the easiest of them all." . But the two appeared on good terms, with Trump joking about the fact that Macron had been asked about it. He's also badgering allies to meet a 2 percent target that only five of the 29 members now meet.