The Spanish Air Force fighter jet was flying alongside one Spanish and two French aircraft when it accidentally launched an air-to-air missile above Estonia.
The president did not clarify which U.S. allies he considers to be ruled by dictators a month after Defense Secretary Mattis hailed NATO as union of "democratic nations."
"Strengthening Russia as an independent international player does not give rest to our NATO colleagues," Russian Defense Minister Sergei Shoigu said.
"This trend clearly indicates that NATO countries are trying in every possible way to prevent Russia from emerging as a geopolitical competitor."
Greece has expelled several Russian diplomats for their alleged interference in the country's foreign policy.
Only 37 percent of Germans believe the continent needs U.S. protection.
Many Americans seem to be buying President Trump’s anti-NATO—and often misleading—rhetoric.
The Republican senator said Trump is "playing right into Putin's hand."
The Balkans could be the first test of whether President Donald Trump will side with NATO or Russia.
When Tucker Carlson asked why his son should be sent to defend Montenegro, Trump said: “I understand what you’re saying. I’ve asked the same question. Montenegro, you know, is a tiny country with very strong people.”
The CEO of Russia's Rostec state corporation said that the company developed "a coating that, like a chameleon, mimics the color of the environment."
The retired four-star general shifted in his seat and looked away as Trump branded Germany a "captive" of Russia, but the White House says he was simply underwhelmed by the catering.
Trump has said the U.S. should spend less but he spent more on Europe's defense, all for a Russian threat he disputes is there.
Trump boasted that the NATO leadership is very fond of him, but says Russia must be thinking "if we did like this guy, we made a big mistake."
It was the first time Russia attempted to use violence outside of the former Soviet Union to achieve its political aims, a report said.
The letters said America's contribution to the NATO alliance is "no longer sustainable."
“We want to send a clear message to any potential adversaries that NATO is there to protect all allies against any threat," said NATO Secretary General Jens Stoltenberg.