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 Korcok 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 Caputova, the country's first female head of state and a staunch backer of neighbouring 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 September 30 parliamentary elections on a pro-Russian and anti-American platform. Pellegrini, 48, who favours a strong role for the state, headed the left-wing Hlas (Voice) party to the third-place finish in the vote and joined a governing coalition with Fico and the ultranationalist Slovak National Party.

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 Jan 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.

The president of the nation of 5.4 million people picks the prime minister after parliamentary elections, swears in the new government and appoints Constitutional Court judges. The president can also veto laws, though Parliament can override the veto with a simple majority, and challenge them at the Constitutional Court. The head of state also has the right to pardon convicts.

The government, led by the prime minister, holds most executive powers.