Marco Rubio warns in no uncertain terms why a no-fly zone over Ukraine is a bad idea: 'It means World War III'

Sen. Marco Rubio (R-Fla.) warned Sunday that establishing a no-fly zone over Ukraine would trigger World War III.

What is a NFZ?

A no-fly zone, otherwise known as an air-exclusion zone, is an order banning aircraft over a certain area.

In war, such aerial demilitarized zones are intended to prohibit military aircraft from engaging in bombing runs and other hostile actions. Military enforcement is thus required, which includes shooting down aircraft that violate the no-fly order. In this situation, if NATO were to establish a no-fly zone over Ukraine, enforcement would mean NATO forces engaging Russian aircraft.

What did Rubio say?

Speaking on ABC News' "This Week," Rubio explained that imposing a no-fly zone over Ukraine would trigger another world war because enforcing a NFZ requires willingness "to shoot down the aircrafts of the Russian Federation."

"Look, a no-fly zone has become a catchphrase. I’m not sure a lot of people fully understand what that means," Rubio began.

"That means flying [Airborne Warning and Control Systems] 24 hours a day. That means the willingness to shoot down and engage Russian airplanes in the sky. That means, frankly, you can’t put those planes up there unless you’re willing to knock out the anti-aircraft systems that the Russians have deployed — and not just in Ukraine, but in Russia and also in Belarus," he explained.

"So basically a no-fly zone, if people understood what it means, it means World War III. It means starting World War III," Rubio warned.

During a video conference with members of the U.S. House and Senate on Saturday, Ukrainian President Volodymyr Zelenskyy essentially asked for a no-fly zone to stop Russia's bombardment of his country.

NATO has refused thus far to establish a no-fly zone over fears that doing so would escalate the war, just as Rubio predicts it would.

"The only way to implement a no-fly zone is to send NATO fighter planes into Ukrainian airspace, and then impose that no-fly zone by shooting down Russian planes," NATO Secretary-General Jens Stoltenberg said. "We understand the desperation, but we also believe that if we did that, we would end up with something that could end in a full-fledged war in Europe."

Russian President Vladimir Putin said over the weekend that imposing a no-fly zone over Ukraine would be viewed by the Kremlin as participation in the war.