Paris, Sep 1 (IANS): Just hours before the summer transfer window of Ligue 1 closed, the 18-year-old forward Kylian Mbappe joined Paris Saint-Germain from defending champions Monaco on a season-long loan, with an option to buy for the capital club.

"The international French striker is transferred on a loan basis from AS Monaco until June 30 2018," PSG said in a statement on Thursday, reports Xinhua news agency.

"The loan agreement also includes a call option for Paris Saint-Germain which, when exercised, will bind the player to Paris Saint-Germain until June 30, 2022," it added.

Mbappe can reportedly be second most expensive player around the world after his new teammate Neymar, who cost PSG 222 million euros ($264 million) during this transfer window.

Mbappe stormed to fame in the second half of last season, steering Monaco to their first French top-flight league crown since 2000, and a semi-final berth in Champions League.

Mbappe scored 15 goals in 29 Ligue 1 appearances in his first full season. He notched 27 goals and 16 assists in 60 matches of all competitions since his first team debut in December 2015. He had six goals in six Champions League knockout games last season.

Mbappe made his debut for French national team on March 25 in Luxembourg, and has made four appearances.

"It is with great joy and pride that I join Paris Saint-Germain. For any young person from the Paris region, it is often a dream to wear the red and blue jersey and experience the unique atmosphere of the Parc des Princes," Mbappe said after signing the contract.

Besides losing the Ligue 1 title contest to Monaco, PSG also suffered a miserable exit from Champions League as they wasted a four-goal lead in the first half to be eliminated by Barcelona in round of 16.

After recruiting Neymar and Mbappe, PSG could expect much more than a Ligue 1 title now.

"I really wanted to be a part of the club's project, which is one of the most ambitious in Europe. Alongside my new teammates, I intend to continue my progression while helping the team achieve the very big objectives it has set itself," Mbappe pointed out.

"It was essential for French football that we keep and help develop such a great talent in our championship.

"Among players of his age, he is without doubt the most promising in the world due to his immense technical, physical and mental qualities," commented Nasser Al-Khelaifi, President of Paris Saint-Germain," he added.