By Alisha Haridasani

Barely hours into the NATO summit in Brussels, President Trump has already spurned key allies and ramped up criticism against the organization.

Trump on Wednesday accused Germany of being a “captive of Russia” for using Russian oil and gas. He also, once again, called on other countries in the military alliance to increase their contribution to defense spending.

German Chancellor Angela Merkel pushed back, though, reminding the president that she knows what it's really like to be occupied by the Soviet Union.

“I have experienced myself how a part of Germany was controlled by the Soviet Union. I am very happy that today we are united in freedom,” she said. “Because of that we can say that we can make our independent policies and make independent decisions.”

She also pointed out that while Germany doesn’t contribute as much towards NATO’s defense spending as America, it is “the second largest provider of troops.”

The president of the European Council, Donald Tusk, also warned the president to “appreciate your allies.”

“After all, you don’t have that many,” he said on Tuesday before the summit officially got underway.

Trump has long voiced his opposition to the military alliance, taking particular issue with America’s large contribution to spending compared with other member countries.

NATO set a spending goal for all 29 members in 2014, asking them to aim to contribute 2 percent of their GDP to defense. America currently pitches in more than 3 percent of its GDP, and only four other countries have met the 2 percent target.

Back home, Republican lawmakers see the president’s aggressive demands as a positive.

“This is an objective of NATO that Trump is reiterating,” said Rep. French Hill (R-Ark.). “It’s not a new commitment, and it’s a commitment that predates Mr. Trump’s presidency. I’m fully supportive of it.”

A few days after meeting with NATO, an alliance that was founded after WWII to counter Soviet Union aggression, Trump will meet with Russian president Vladimir Putin one-on-one in Helsinki, Finland.

That meeting, which Trump has said “may be the easiest of them all,” is a source of concern for American allies and lawmakers alike, who worry that he may make too many concessions.

Members of the House Foreign Affairs Committee on Tuesday sent the president a letter, urging him to “not praise, condone, or abet any Russian efforts to undermine the sovereignty or democracy of any of our allies and partners.”

“President Trump must recognize the importance that our forward military presence and joint military exercises play in deterring Russia and ensuring military readiness,” the letter states, responding to reports that the Pentagon is considering reducing America’s military presence in Europe and alluding to Trump’s decision to end military exercises on the Korean peninsula after meeting with North Korean leader Kim Jong-un.

“This president says ‘America First’ but it seems as though he’s saying ‘Russia First’ or ‘North Korea First’,” said Rep. Gregory Meeks (D-NY) who sits on the House committee that wrote the letter. “It seems as though this president enjoys to give away the store to individuals who have been antagonistic towards us.”