Pro-Russian parties in Serbia are demanding that a referendum be held next month, together with general elections, which would prevent the country from joining NATO.

The demands were voiced Thursday on the 17th anniversary of the start of the NATO bombing of Serbia over its bloody crackdown against Kosovo Albanian separatists.

Bosko Obradovic of the right-wing Dveri party says that if the incumbent populists remain in power in Serbia after the April 24 elections, they will seek NATO membership and will join Western sanctions against Russia over Ukraine.

The current government has so far refused to impose sanctions against longtime Slavic ally Russia, despite seeking EU membership. It has also said the country should remain militarily neutral.

NATO remains highly unpopular in Serbia after the 78-day bombing in 1999.