LISBON -- Center-left Socialist Party candidate Antonio Jose Seguro declared victory in Portugal's second-round presidential election on Sunday.

According to data from the interior ministry, 99.2 percent of the ballots have been counted so far, with Seguro winning 66.8 percent of the vote and far-right Chega leader Andre Ventura securing 33.2 percent. Ventura has conceded defeat.

Seguro secured the highest number of votes ever in a Portuguese presidential election since 1976, garnering 3,477,717 votes, with results from 21 parishes and eight consulates still to be counted.

In his victory speech on Sunday night, Seguro said that he would govern with independence, treat all political parties and social partners impartially, and foster collaboration with both parliament and the government.

He emphasized that he would not position himself as a confrontational hub of power, expressing hope that political parties, parliament and the government would join forces to find enduring solutions to pressing challenges confronting Portuguese society, such as healthcare, housing, employment and poverty.

This marks the first time in roughly four decades that a presidential contest in the country has advanced to a runoff. In the initial round, Seguro emerged as the frontrunner, securing approximately 31 percent of the vote, while Ventura came in second with 23.5 percent. Chega, which experienced rapid growth last year, has since established itself as one of the key political forces in Portugal's parliament.

As a long-standing figure within the Socialist Party, Seguro presented himself as a moderate candidate, openly challenging Ventura's radical political agenda and garnering support from a host of mainstream political figures across both the left and the right. Many political entities viewed the election as a pivotal moment to stem the further ascent of populism and far-right forces in Portugal.

Outgoing President Marcelo Rebelo de Sousa said that he had phoned Seguro to congratulate him on his victory.

In a statement published on the presidency website, de Sousa said that he will receive Seguro at Belem Palace on Monday afternoon.

According to the statement, de Sousa wished Seguro "every success and fulfilment in the mandate entrusted to him by the Portuguese people, which will begin on March 9," and expressed his full availability to ensure a smooth institutional transition.