A leftist opposition party calling for suspending military aid to Ukraine is set to win the largest number of seats in Slovakia's parliamentary election.

The country's statistics office said the Smer-SSD party of former Prime Minister Robert Fico led with about 23 percent of the votes, with 99.56% of ballots counted in Saturday's election.

The central European country's current government has provided military support to neighboring Ukraine.

Slovakia became the first NATO member state to send fighter jets to Ukraine, and was aligned with the European Union on sanctions on Russia.

During the election campaign, Fico's party argued that the sanctions caused price surges and hurt Slovaks.

However, the party is falling short of a majority in the parliament and is expected to negotiate with other parties to form a coalition government.

Observers say the outcome of the negotiations could affect the unity of the EU, which is supporting Ukraine.

Attention is focused on whether Slovakia will halt military support for Ukraine if Fico's party comes to power.