A populist party that wants to stop military aid to Ukraine and is critical of the EU and NATO has won Slovakia's election, results showed on Sunday.

The Smer-SD party led by former Prime Minister Robert Fico earned 23.3% of the vote, beating the centrist Progressive Slovakia on 17%, with almost all votes counted.

Analysts predict a Fico government could radically change Slovakia's foreign policy to resemble that of Hungarian Prime Minister Viktor Orban.