Croatia said Wednesday it will purchase upgraded Israeli F-16 fighter aircraft as it seeks to bolster its defenses amid Russia’s arming of neighboring Serbia.

Once formally approved by the government, it will be Croatia’s largest single military deal since it split from Serb-led Yugoslavia in the bloody 1991-95 war.

Croatia’s Defense Council accepted an Israeli offer that will replace the country’s aging MiG-21 fighters, of which only six are believed to be operational.

The military experts did not specify details of the deal, but previous reports have said it involves 12 used F-16 aircraft worth some $500 million that have been heavily modified with Israeli-made avionics.

Sweden’s manufacturer Saab had offered a squadron of new Gripen fighters, but the package was reportedly estimated at some $700 million. Other bids came from the U.S., Greece and South Korea.

“If Croatia was a richer country, and if our economy was stronger, maybe we could have picked a more expensive offer,” Croatian Prime Minister Andrej Plenkovic said. “But, based on the parameters presented to us by our expert team, we believe that we have made a responsible decision which will meet all the needs of the Croatian air force in the next 30 years.”

NATO member Croatia faces a mini arms race with Russian ally Serbia, which recently received six used Russian MiG-29 fighter jets and will be armed with dozens of tanks, armored vehicles, helicopters and transport planes.

With the buildup of Serbia’s military, Moscow is attempting to increase its influence in the Balkans.

(AP)