Peter Pellegrini, a close ally of left-wing populist Prime Minister Robert Fico, was sworn in as president of Slovakia on Saturday.
The 48-year-old took the oath of office in a ceremony at the Slovak Philharmonic in Bratislava in front of members of parliament.
Pellegrini won the run-off election in April with 53.1% of the vote, beating out former foreign minister Ivan Korčok.
Ukraine featured prominently in the campaign, with Pellegrini advocating a cautious stance on arms deliveries to Kiev - a position that is in line with Russia-friendly Fico.
Pellegrini previously served as prime minister from 2018 to 2020 and as parliamentary speaker.
The incumbent Zuzana Čaputová, a lawyer and rights activist, did not run for a second five-year term despite her continued popularity as president.
Pellegrini's Voice - Social Democracy party is part of Slovakia's governing coalition, led by Fico. The right-wing populist Slovak National Party (SNS) is also part of the fractious coalition.
Presidents in Slovakia have few executive powers, although they can veto laws. The president is commander-in-chief of the armed forces and represents the country of nearly 5.5 million in visits abroad.
With the swearing-in of Pellegrini, the left-wing nationalist camp now holds the two most important political offices in the country.
The opposition fears that the coalition will now push through controversial plans such as the proposed dissolution of the public radio and television broadcaster RTVS.
Slovakia and its fellow EU members were stunned by an assassination attempt against Fico last month that left the prime minister seriously injured.
