Red Bull driver Max Verstappen says only a winning car will make him stay with the team for the long term.

The precocious Dutchman, viewed by many as the most talented driver on the grid, has endured a frustrating campaign so far this season.

Reliability issues have dogged him throughout, with the 19-year-old retiring from nearly half his Grand Prix starts in 2017.

Last month, Christian Horner dismissed speculation of him joinng Ferrari as "propaganda" but Verstappen says he will not be patient for too long.

"I've always said that there's no reason to leave when I have a competitive car," Verstappen said during a visit to the DTM paddock for its Zandvoort round at the weekend.

"At the moment we are not there where I want to be, but that doesn't mean you have to give up straight away. You have to work hard."

"But after two, three years without improving, that would be a different story."