The stop-start affair that is Six Flags' expansion into Chinese territory may never come to fruition it seems after the US theme park operator revealed continuing problems with its partner in China.

The company said in a regulatory filing that real estate developer Riverside Investment Group had defaulted on payments "due to a declining market" and that the development of Six Flags-branded parks in China had "encountered continued challenges and has not progressed as expected".

"While the company continues to work with Riverside the eventual outcome is unknown and could range from the continuation of one or more projects to the termination of all the Six Flags-branded projects in China," said the statement.

Six Flags' first Chinese park – at Zhejiang Province – was scheduled to open in 2020, although this would seem far from certain now. Additional projects in Nanjing and Chongqing have also been subject to delays.

In October 2019, Six Flags CEO Jim Reid-Anderson spoke of the frustrations the company was facing in getting its China projects off the ground, saying "part of it is our partner, part of it is the economy, part of it is the local government saying this is when we can have everything ready for you in order to be able to open a park".

The company also had to shelve plans for a Dubai theme park last year, after funding problems with its partner DXB Entertainments.