BELGRADE, Serbia (AP) — Serbia on Saturday publicly displayed a recently delivered Chinese anti-aircraft missile system, raising concerns in the West and among some of Serbia’s neighbors that an arms buildup in the Balkans could threaten fragile peace in the region.

The sophisticated HQ-22 surface-to-air system was delivered last month by a dozen Chinese Air Force Y-20 transport planes in what was believed to be the largest-ever airlift delivery of Chinese arms to Europe.

Although Serbia officially seeks membership in the European Union, it has been arming itself mostly with Russian and Chinese weapons, including T-72 battle tanks, MiG-29 fighter jets, Mi-35 attack helicopters and drones.

Back in 2020, U.S. officials warned Belgrade against purchasing HQ-22 missile systems, whose export version is known as FK-3. They said that if Serbia really wants to join the EU and other Western alliances, it must align its military equipment with Western standards.

The Chinese missile system has been widely compared to the American Patriot and the Russian S-300 surface-to-air missile systems although it has a shorter range than more advanced S-300s. Serbia is the first operator of the Chinese missiles in Europe.

Serbian President Aleksandar Vucic said at the end of the arms display at a military airport near Belgrade that the Chinese missiles, as well as other recently delivered military hardware, are not a threat to anyone and only represent a “powerful deterrent” against potential attackers.

“We will no longer allow to be a punching bag for anyone,” Vucic said, apparently referring to NATO’s 78-day bombardment of Serbia for its bloody crackdown against Kosovo Albanian separatists in 1999.

Serbia, which was at war with its neighbors in the 1990s, does not recognize Kosovo’s independence declared in 2008. It still has frosty relations with NATO-members Croatia and Montenegro as well as Bosnia, whose separatist Bosnian Serb leader Milorad Dodik attended the military drill on Saturday.

Vucic said Serbia is also negotiating a purchase of French multi-purpose Dessault Rafale jets, as well as British Eurofighter Typhoon fighters. He said that only “political hurdles” could prevent the purchase of the Western aircraft.

There are widespread concerns that Russia could push its ally Serbia into an armed conflict with its neighbors to try at least partly to shift public attention from the war in Ukraine.

Although Serbia has voted in favor of U.N. resolutions that condemn the bloody Russian attacks in Ukraine, it has refused to join international sanctions against its allies in Moscow or outright criticize the apparent atrocities committed by the Russian troops in Ukraine.