In comments that could have significant repercussions if he becomes the next American president, Republican presidential nominee Donald Trump said Wednesday that the U.S. would not automatically come to the defense of NATO allies if Russia attacks them. Rather, he would, under his presidency, only aid these nations if they “have fulfilled their obligations to us.”

“If they fulfill their obligations to us, the answer is yes,” Trump said in an interview with the New York Times on the eve of his acceptance speech at the Republican National Convention in Cleveland.

“This is not 40 years ago,” Trump said, reiterating his insistence that other countries should share more of the defense costs the U.S. is currently bearing. “We are spending a fortune on military in order to lose $800 billion. That doesn’t sound very smart to me.”

Trump’s comments come at a time when Russia has slammed NATO’s decision to deploy troops in Eastern Europe. Last month, ahead of a summit in Warsaw, the 28-nation alliance announced that it will deploy four multinational battalions to the Baltic states and Poland — countries that are seeking to boost their defenses against Russia. The nations’ increased push to guard their borders against Moscow is primarily driven by Russia’s annexation of Crimea in 2014 and its ongoing support for rebels in eastern Ukraine.

Russia, however, has decried the troop deployment as part of NATO’s “confrontational agenda.”

In the interview, Trump also said that he would not criticize the Turkish government for cracking down on political opponents — something that many fear the Recep Tayyip Erdoğan-led administration may do in the garb of punishing those it believes were responsible for the recent failed coup.

“I don’t think we have a right to lecture,” Trump said, adding that the U.S. should fix its own mess before trying to alter the behavior of other countries.

“Look at what is happening in our country. How are we going to lecture when people are shooting policemen in cold blood?” Trump said, referring to the recent spate of violence against law enforcement officials in the U.S. "When the world sees how bad the United States is and we start talking about civil liberties, I don’t think we are a very good messenger."