Robert Fico will not change his views on Ukraine even if it would lead to Smer's exclusion from the Party of European Socialists (PES), the Slovakian politician said in a video posted on social media.

Fico's remarks come after PES leader Stefan Lofven threatened to exclude Smer due to its leader's stance on the conflict between Ukraine and Russia.

Smer won Slovakia's parliamentary election which took place on Saturday, granting Fico the right to form a government in the Central European country.

Fico, who has a strong stance against providing military aid to Ukraine, said that Lofven's statements are "blackmail", adding that he expected to be congratulated rather than threatened.

Lofven said that if Fico's rhetoric on Ukraine turns into government action, he will start Smer's expulsion process from the European group.

"If our exclusion from the international party is to be a price for pursuing a genuine left-wing agenda in Slovakia and voicing sovereign opinions, we are prepared to pay such a price," Fico said.

Read more: Slovakia election keeps West on toes amid pro-Russia shift in Europe

European leftists irked by Smer's anti-NATO stance

Fico said that Lovfen's threats are "undemocratic and authoritarian," reiterating that his party had condemned Russia's use of force in Ukraine but his party's views on a peaceful resolution to the conflict will not change.

The leftist Smer party, like other non-aligned movements, has called on the European Union to a diplomatic solution through negotiation between Ukraine and Russia instead of fueling the conflict by sending weapons to Ukraine.

Fico has famously said that his government would only provide humanitarian aid to Ukrainians and meet its financial obligations to the country, however, it would not send "a single round" to Kiev.

He has previously likened NATO forces stationed in the country to "Nazis" and said that "Ukrainian fascists" are to blame for the ongoing conflict in Ukraine.

Leaders of the European Green Party have said that Smer's continued membership in the PES is "not understandable".

The Greens/EFA Group claimed that Smer is openly spreading "Kremlin disinformation", urging the European Parliament to decide the party's fate.

Read more: Kiev on shaky grounds as Poland, Slovakia cut arms supplies