The French club have reacted to speculation suggesting a two-year deal for the Argentinian is imminent by publishing a video teasing his arrival.
The 13-second clip on the club’s Twitter account features what appears a brief image of a footballer in an Argentina number 10 shirt and a picture of the PSG dressing room with an Argentina flag hanging above a seat.
It is accompanied by the words, “New diamond in Paris”.
The club have also called a press conference for Wednesday morning.
Messi was pictured in France on Tuesday wearing a T-shirt with the club’s trademark “Ici c’est Paris” (This is Paris) on the front after flying over from Barcelona earlier in the day.
The 34-year-old’s father and agent, Jorge Messi, also appeared to confirm the move when he was met by reporters at Barcelona airport.
Asked if it was happening, he seemed to say: “Yes.”
Messi’s wife Antonela then posted an update on her Instagram account which read, “All together towards a new adventure” alongside a picture of the pair on an aeroplane.
Messi has spent all his career to date at Barcelona after joining the Catalan club at the age of 13.
He is their record goalscorer with 682 and has won 35 trophies.
He had hoped to stay at the Nou Camp but the club announced last week they were unable to renew his contract due to financial difficulties, despite the player accepting a pay cut.
Messi became a free agent when his previous deal expired at the end of last season.
He bade a tearful farewell to Barcelona at a press conference at the weekend.
PSG were immediately linked with his services and his signing now seems close to being finalised.
The move would see him link up with his former Barcelona team-mate Neymar, who also appeared to welcome Messi to Paris with a social media message.
The Brazil star posted the words ‘Back together’ above a montage of the duo’s best goals and assists from their time together in Catalonia on his Instagram account.