Popescu, 26, played 21 times for the Paisley club last term after joining on loan from Dinamo Bucharest in January.

The centre-back helped St Mirren preserve their Scottish Premiership status, scoring in the shootout of the play-off final win over Dundee United.

The club say they "believed we had reached agreement" for another loan.

"However, unfortunately demands from Mihai's representatives changed and became unrealistic," a club statement added.

"We are disappointed that we were unable to reach an agreement with Mihai but we continue to press on with other targets."

Popescu is under contract with Dinamo until summer 2021, and the the Romania club were demanding £350,000 to make the move permanent.

Speaking before Oran Kearney departed as manager last week, Popescu said he was keen to stay "but my future is not sure".