WASHINGTON (AP) — President Donald Trump is taking another jab at NATO, questioning whether the alliance's mutual defense pact might conceivably let tiny Montenegro's "very aggressive people" start World War III.

Trump commented in an interview with Tucker Carlson of Fox News Channel that aired Tuesday night. The interview was conducted Monday after the Helsinki summit.

Trump and Carlson were discussing NATO when the Fox News host questioned why his son should have to defend Montenegro if it's attacked. Russia was irked when Montenegro joined NATO in 2017.

The president replied that he's asked the same question. Montenegro "may get aggressive and congratulations, you're in World War III," Trump said.

Trump is a longstanding skeptic of NATO. A scenario where tensions over Montenegro would trigger nuclear war seems unlikely.