Donald Trump. Spencer Platt/Getty Images If President-elect Donald Trump's recent statements on the European Union and NATO are any indication, his administration could bring unprecedented changes to longstanding alliances among Western countries.

In an interview published Sunday with the Times of London and Bild newspapers, Trump questioned the value of the North Atlantic Treaty Organization alliance when he was asked whether he understood why many in Eastern Europe feared Russian aggression.

"I said a long time ago — that NATO had problems," Trump told The Times and Bild. "Number one it was obsolete, because it was, you know, designed many, many years ago. Number two — the countries aren't paying what they're supposed to pay."

He also appeared indifferent toward the EU.

"People want their own identity, so if you ask me, others, I believe others will leave," Trump said of the political and economic union. He also said that the EU's future didn't matter much for the US.

The Soufan Group, a strategic-security firm, noted on Tuesday that these statements "have generated concerns of potentially unprecedented changes in US foreign policy" toward Europe.

"The notion that the lead-up to the 2017 US presidential inauguration would involve skepticism over the durability of NATO likely would have drawn disbelief several years ago," the note said.

The note added that "even the suggestion of the US taking a less robust role in leading or supporting NATO is without precedent." NATO receives significant support financially and militarily from the US, and Trump has hinted that the US might not honor its commitments to collective defense if member countries don't meet certain terms.

Still, The Soufan Group noted that it was unclear how Trump's statements would translate into actual policy. And Rex Tillerson, the former Exxon Mobil CEO who is Trump's nominee for secretary of state, has said NATO's Article 5 collective-action agreement is "inviolable" and that the US will stand by it. Trump also said during his interview with The Times and Bild that NATO was "very important to him."

"The challenge facing EU and NATO members is to prepare for the possibility of dramatic changes while not overreacting to what are still just informal statements; that these statements have been made by the individual who will assume the US presidency on January 20 is what gives them their instant gravity and potential for serious consequences," the Soufan note said.

"It remains to be seen how much of the rhetoric will become reality, but recent trends suggest the US approach to foreign policy — and even dealing with long-standing allies — may soon be subject to significant change."

European leaders are watching Trump's statements carefully. The Washington Post reported that some leaders weren't counting on support from the US during the Trump presidency.

German Chancellor Angela Merkel told reporters in Berlin recently that Europeans "have our destiny in our own hands."

Natasha Bertrand contributed to this report.