A pro-Western former top diplomat and a Ukraine-sceptic backed by the ruling populists will face off in a presidential election on Saturday that could possibly halt Slovakia's shift towards Russia.

Russia's invasion of Ukraine has become a fixture of the electoral campaign in Slovakia, a European Union and NATO member of 5.4 million people.

The two candidates, Peter Pellegrini and Ivan Korcok, are vying to replace outgoing liberal President Zuzana Caputova.

They will square off in a decisive second round as neither won the minimum 50 percent of votes in the first ballot on March 23.

The latest polls suggest the candidates are running nearly neck-and-neck.

Pellegrini, the 48-year-old parliament speaker, is credited with 51 percent of the vote and Korcok with 49 percent, according to the NMS agency opinion survey.

Russia's war in Ukraine, now in its third year, has become a key election issue.

Populist Prime Minister Robert Fico -- a Pellegrini ally -- has questioned the sovereignty of Ukraine and called for peace with Russia.

Korcok, a 59-year-old career diplomat and vocal government critic backed by the opposition, is staunchly pro-Kyiv.

- 'Leaning towards Russia' -


Analysts said Slovakia's foreign policy would continue to be a major topic in the run-off campaign.

"If Korcok is elected, Slovakia will maintain a critical attitude towards Russia, pro-European positions and support for Ukraine," said analyst Grigorij Meseznikov.

Pellegrini, in turn, "will support ... loosening our ties with our allies and partners in NATO and the EU, weaker support for Ukraine and leaning towards Russia", he told AFP.

Pellegrini was a minister in previous Fico governments.

He became prime minister in 2018 after his long-time ally was toppled as premier. Fico became prime minister again in 2023.

"I am running for president to rescue the government of Robert Fico," Pellegrini said in a televised debate with Korcok after the first round.

"You want to protect the government. I want to protect Slovakia," Korcok told his opponent.

The government, in office since last October and comprising Fico's Smer party, Pellegrini's Hlas and the small far-right SNS, has discontinued military aid to Ukraine.

"Ivan Korcok is a warmonger who will support everything the West tells him without hesitation, including dragging Slovakia into the war," Fico said in a video, adding that he supported Pellegrini.

"Peter Pellegrini is a moderate candidate who recognises the value of peace," he added.

- 'Good advocate for Slovakia' -


The rivals know they will have to woo people who voted for the other seven candidates in the first round.

Third-placed Stefan Harabin, who won almost 12 percent after criticising the European Union and hailing Russian President Vladimir Putin, has not formally supported either of the two ahead of the run-off.

"My voters will know what to do," Harabin said after the first round.

According to a poll from the AKO agency, over two-thirds of Harabin voters intend to back Pellegrini.

In one of the televised pre-election debates, Pellegrini said he could "offer Stefan Harabin's voters the type of politics they are asking for".

Bratislava-based engineer Vojtech Hromada told AFP he believed Korcok would "be a good advocate for Slovakia abroad".

"He is a good diplomat and he has represented us throughout the world," the 44-year-old said.

Psychologist Vladka Abrusova, 34, said she would support Pellegrini for his political experience and calm disposition.

"He never disappointed while holding public office and he radiated serenity and composure," she said.

Slovakia's president ratifies international treaties, appoints top judges, is the commander-in-chief of the armed forces and can veto laws passed by parliament.

Polling stations open on Saturday at 7:00 am (0500 GMT) and close at 10:00 pm.