Red Bull's Mark Webber has cast doubt on whether he will stay at the team next year.

Team boss Christian Horner said on Thursday Webber had "made it clear that he wants to drive next year" and they would discuss it later this season.

But on Friday Webber said: "We'll see how we go. There's a bit to go yet in the summer. [I'll] keep thinking."

The Australian, who turns 35 this year, agreed with Horner last season that they would only do one-year contracts.

Before signing up for 2011, Webber spent some time in the spring considering whether he wanted to carry on racing and he has talked earlier this season about needing to make the same decision again.

Speaking to BBC Sport on Friday following Webber's comments, Horner repeated his line from Thursday, adding: "He's comfortable within the team, he enjoys driving for Red Bull, things are always fairly straightforward when you deal with Mark.

"At the appropriate time we'll sit down and talk about 2012 but probably not just at the moment."

Pressed on whether they had discussed the future recently, Horner said: "Any discussions between the team and the driver will remain confidential but he has made it quite clear he would like to remain with the team next year."

Asked why Webber had made his remarks if he had said he wanted to stay with the team, Horner shrugged his shoulders.

He added: "Mark's a very popular member of the team, he's been with the team a long time now.

"He's doing a good job but as we agreed 12 months ago at this stage of the year rather than rushing into lengthy agreements we agreed to do things one step at a time.

"Considering we're only six races into this season, it's a bit too early at this stage to be focusing on next year. We're happy with what he's doing and at some stage in the summer we'll sit down and talk and talk about next year."

Webber led the championship for much of last season, eventually finishing third behind team-mate Sebastian Vettel and Ferrari's Fernando Alonso.

But this season Webber has struggled to match Vettel, who has won five of the first six races.

Webber has pinpointed this year's new Pirelli tyres, which have replaced last year's Bridgestones, as the root of his problems.

Horner said: "Let's not forget he's up against the most in-form driver. Sebastian has made a massive step this year.

"Mark has found it harder to adapt to the Pirelli tyres and make the most out of them. It's a tough challenge but I'm sure given another couple of races he'll be right there."