President Donald Trump repeatedly expressed to senior White House aides his desire to withdraw from the North Atlantic Treaty Organization, according to a report.

The military alliance created in the aftermath of World War II by the United States, Canada and some European nations has been viewed as a critical bedrock against Soviet and Russian aggression for decades. But Trump has long balked at the U.S.'s NATO allies for not spending more on defense and meeting funding commitments.

The revelation that the president did not see the point of the alliance and discussed withdrawing from it last year, reported in the New York Times on Monday evening, comes amid allegations that Trump deliberately concealed details of his meetings with Russian President Vladimir Putin, even from his own aides. It also comes amid a separate Times report that the FBI launched an investigation into Trump's administration over whether he was secretly working on behalf of the Russians.

A weakened NATO is one of Putin's major geopolitical goals and fears of its eastward expansion is one of the reasons often cited for Russia's seizure of Ukraine's Crimea.

The White House said that while Trump has publicly raised complaints about NATO, he seems satisfied with the way things stand now. It also pointed to statements he made in July in which he said NATO was "very important."

Trump's strong aversion to international alliances and organizations is well documented. He pulled the U.S. out of the Paris climate change accord and exited a sweeping trade pact with Asian nations, as well as a deal related to Iran's nuclear weapons program.

Trump has previously, publicly appeared to threaten to withdraw the U.S. from NATO if allies don't boost military spending. He has accused key NATO partners of being freeloaders and described the alliance as "obsolete."

"I think it's the most insulting thing I’ve ever been asked," Trump replied in a TV interview when asked about the FBI's probe. "I think it's the most insulting article I’ve ever had written. And if you read the article, you'd see they found absolutely nothing."

NATO was founded in 1949 and has 29 members. All have agreed to spend 2 percent of their gross domestic product on defense by 2024. The alliance has estimated that based on current trends only half of NATO members will reach this target.

"It doesn't get much worse than this," Carl Bildt, a Swedish diplomat and former prime minister, tweeted Tuesday reacting to Trump's reported NATO discussions.

NATO was was founded on the principle of collective defense, meaning if one NATO ally is attacked, all NATO allies are attacked. In recent years, NATO forces have been deployed to Estonia, Latvia, Lithuania and Poland to act as a bulwark against Russian territorial hostility. They also help combat terrorism in Afghanistan, commercial piracy off the Horn of Africa and address global migration-related issues.

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Contributing: David Jackson in Washington