His current deal expires in 12 months' time.
"Radu wants to stay at Lazio, but first we need an agreement with President Lotito. The lad could even go to the end of his contract," agent Victor Becali told Radio Manà Manà.
"There have been no developments since we made contact last week. I haven't heard from Lotito.
"As soon as the President calls, then we are ready, there are no problems on our end. We can only wait, as there's nothing else we can do.
"We have not talked to any other clubs, as that would not be fair. Radu is a Lazio player and wants to stay in Rome.
"Having said that, it's obvious that if we do not reach a deal then the player could see his contract reach expiry."