Updated

Russian and Serbian officials say Serbia is seeking a Russian air-defense system in addition to fighter jets and battle tanks.

Serbian Prime Minister Aleksandar Vucic has said he negotiated the purchase of the S-300 anti-aircraft rockets during his recent talks with Russian President Vladimir Putin.

Although Serbia claims it wants to be part of the European Union, it has been strengthening military, economic and political ties with Slavic ally Russia, which is trying to increase its influence in the war-weary Balkans.

The purchase has been overshadowed in Serbia by reports from rival Croatia that during the war for independence from Serb-led Yugoslavia in the 1990s Russian supplied Croatia with the same system — a potential breach of a U.N. arms embargo at the time.

Russia's Defense Ministry said Tuesday the reports are aimed at undermining Moscow's relations with Serbia.