Romania has claimed a Russian drone entered its airspace Saturday near Ukraine's southern border, a move Ukrainian President Volodymyr Zelensky called an expansion by Russia in the ongoing war.

After Romania reported that a Russian drone had violated its airspace, days after Poland shot down multiple Russian drones in its airspace, Ukrainian President Volodymyr Zelensky said the violations were not an accident and that Russia "knows exactly where their drones are headed." Photo by Aaron Schwartz/UPI UPI

Sept. 14 (UPI) -- Romania has claimed a Russian drone entered its airspace Saturday near Ukraine's southern border, a move Ukrainian President Volodymyr Zelensky called an expansion by Russia in the ongoing war.

"The Russian military knows exactly where their drones are headed and how long they can operate in the air," a social media statement by Zelensky said. "Their routes are always calculated. This cannot be a coincidence or a mistake or the initiative of some lower level commanders."

Romania is the second NATO country to report such an incursion. On Wednesday, Poland said it had shot down three drones that had breached its airspace, according to the BBC.

Romania said it detected the Russian drone when a pair of F-16 jets were monitoring its border with Ukraine, according to a statement from the Romanian defense ministry.

It said the drone was detected about 12 miles southwest of the village of Chilia Veche before it disappeared from radar.

"The UAV did not fly over populated areas and did not pose an imminent threat to the security of the population," the statement said. It said the defense ministry has teams on alert to monitor potentially hazardous fallout from the drone.

"People in Romania were never in danger but such actions by Russia are unacceptable and reckless, a social media post from the Romanian minister of foreign affairs said.

It is the latest incident in an ongoing series of escalations in the war between Russia and Ukraine, the latest chapter of which has been waged since February 2022.

Moscow has not commented on either incident.