Renault needs Daniel Ricciardo to take a leap of faith if the French Formula One team are to retain the Australian beyond this season, says four-time world champion Alain Prost.

The 64-year-old Frenchman is a special advisor to Renault's F1 outfit, and after the team spluttered to a fifth-place finish in last season's constructors' championship, Prost believes Renault must edge closer to the front-running Mercedes, Ferrari and Red Bull Racing triumvirate in 2020 to keep Ricciardo in their stable.

Ricciardo, 30, joined Renault on a two-year deal last season after five successful years at Red Bull, where he finished third in the drivers' standings twice, won seven grands prix and finished 22 other races on the podium.

While Red Bull finished third in the teams' and drivers' standings last year with Ricciardo's former teammate Max Verstappen, Ricciardo managed a best result of fourth place at the Italian Grand Prix and finished ninth overall, his worst showing since 2013.