Ross Brawn says official tyre supplier Pirelli has work to do to spice up the F1 show.

Liberty Media's F1 sporting boss says the recent Mexican grand prix was another example of the "two-class society" currently in play on the grid.

"Apart from the usual differences in performance, tyre management was also responsible," Brawn, referring to the on-track spectacle in Mexico, is quoted by Speed Week.

"Nico Hulkenberg, Charles Leclerc, Stoffel Vandoorne and Marcus Ericsson did just one pitstop and all four were very cautious to make it to the finish on the same tyre," he said.

Brawn said it wasn't good for the show, but he acknowledged that Pirelli's engineers are grappling with a "difficult challenge".

"On the one hand they have to bring tyres that degrade and make for exciting races, but on the other the drivers want to fully exploit the potential of their cars with robust rubber," he explained.

"It's not always easy to find the right compromise, so it's very important that we work together," Brawn said.

Currently, Liberty Media is weighing up whether to stick with Pirelli for the future, or move the teams onto Hankook tyres in 2020.

"It's not our decision," Ferrari team boss Maurizio Arrivabene said, "but personally I would not give up all the experience we have gained in recent years."