Peter Pellegrini, a close ally of the populist prime minister, is sworn in as Slovakia's president

BRATISLAVA, Slovakia — Peter Pellegrini was sworn in as the president of Slovakia on Saturday in a ceremony that took place amid heightened security following an assassination attempt on his close ally, populist Prime Minister Robert Fico, a month ago.

Pellegrini called for national unity in his speech at a special session of Parliament that took place at the seat of the Slovak philharmonic, becoming Slovakia's sixth president since it gained independence after the disintegration of Czechoslovakia in 1993.

''We are one nation, one society, one Slovakia,'' he said.

The 48-year-old Pellegrini beat pro-Western career diplomat Ivan Korčok in the presidential runoff vote on April 6. His victory cemented Fico's grip on power by giving him and his allies control of major strategic posts.

He succeeded Zuzana Čaputová, the country's first female head of state and a staunch backer of neighboring Ukraine in its fight against Russia's invasion. She didn't seek a second term in the largely ceremonial post.

Fico didn't attend the ceremony as he's still recovering after being shot in the abdomen while greeting supporters on May 15 in the town of Handlova. The assailant was arrested.

Fico's leftist Smer (Direction) party won Sept. 30 parliamentary elections on a pro-Russian and anti-American platform.

Critics worry Slovakia under Fico will abandon its pro-Western course and follow the direction of Hungary under populist Prime Minister Viktor Orbán.

The new government immediately halted any arms deliveries to Ukraine. Thousands have repeatedly taken to the streets across Slovakia recently to rally against Fico's pro-Russian and other policies, including plans to amend the penal code and take control of the public media.

Pellegerini, who became Parliament's speaker after the election, never questioned Fico's policies.

He was Fico's former deputy in Smer when he became prime minister in 2018, after Fico was forced to resign following major anti-government street protests over the killing of journalist Ján Kuciak and his fiancee.

Pellegrini had temporarily parted ways with Fico after the scandal-tainted Smer lost the previous election in 2020, but their reunion enabled made the creation of Fico's government.