Paris Saint-Germain have left Kylian Mbappe out of their squad for a pre-season tour of Japan and South Korea, casting further doubt on the forward's future with the French champion.

PSG gave no reason for the omission of France's captain but 24-year-old Mbappe has said for weeks that he might not sign a new contract.

As his teammates flew to Asia, Mbappe trained with the reserve team on Saturday and afterwards greeted young fans outside the club's training complex outside Paris.

A smiling Mbappe posed for selfies and signed photographs and jerseys as one young supporter shouted "Stay with us Kylian".

Access24 feels his omission from the tour might fuel fresh speculation that he could leave to join another team before next season.

The forward declared in May that he did not want to extend his PSG contract, which expires next year, but indicated he wanted to remain at the club for a final season.

"I still have a year left on my contract and I am going to honour my contract," he said.

That would allow him to become a free agent next summer and leave PSG for nothing, a prospect that club president Nasser al-Khelaifi said was "impossible".

"We can't let the best player in the world today leave for free," Khelaifi said.

Khelaifi even gave Mbappe an ultimatum of a "maximum of two weeks" to make his decision -- sign a new contract or leave this summer.

Mbappe, the club's all-time top scorer with 212 goals in 260 appearances, remains the second most expensive player in history.

He was still a teenager when he joined PSG on a season-long loan from Monaco in August 2017.

The move turned into a permanent transfer the following year in a 180-million-euro ($200 million) deal.

The 29-player PSG squad in Asia will include Mbappe's younger brother, 16-year-old Ethan Mbappe, as well as Neymar, the Brazilian whose transfer fee of 222 million euros in 2017 is the world record.