The 25-year-old put pen to paper on a contract until 2023 after completing a medical in Qatar. No transfer fee was disclosed.

"Leandro's arrival will keep the momentum, both on the pitch and among our supporters, ahead of the major events coming up. Exciting times lie ahead," PSG's Qatari president Nasser Al-Khelaifi said in a club statement.

The Ligue 1 leaders were looking to strengthen in midfield ahead of their Champions League last-16 tie against Manchester United, with Marco Verratti sidelined with an ankle injury and Adrien Rabiot frozen out after refusing to sign a new contract.

PSG go to Old Trafford in the first leg of that tie on February 12, and they are currently sweating on the fitness of Neymar, who suffered a metatarsal injury last week.

Paredes, who has won nine caps but was not part of Argentina's squad at last year's World Cup, has previously played for Boca Juniors and Roma. He moved to Zenit in 2017.