Kimi Raikkonen will remain on Red Bull's short list until such a time as the Finn has been confirmed by another team, that's according to Christian Horner.
Raikkonen had been a front runner to replace Mark Webber until earlier this week when his manager Steve Robertson revealed that talks had broken down.
"The negotiations with Red Bull were not successful and ended some time ago," he told Turun Sanomat.
However, Horner insists Red Bull have not ruled out signing the 2007 World Champion.
"Has he signed for anyone else? It's up to him," said the Red Bull team boss. "Kimi's manager ruled him out I think. I've only seen what you've seen."
Horner added that his team won't be rushed into making a decision despite earlier rumours suggesting an announcement would be made at this weekend's Belgian GP.
"I think the problem is you get to this point of the year and there's so many rumours, hearsay, this, that and the other. I saw he [Raikkonen] was going to Ferrari a couple of days ago," he said.
"There is no transfer window in Formula 1. We are not obliged to make a decision until we choose to. As I say, we want to make sure that we make the right decision and we will take the time that we feel appropriate to make that decision."
He added: "You have to make sure you consider all the options and there's more options than you could possibly think.
"There's been quite a lot of interest. So we just take the time. It's not going to be much longer I'd have thought. I'd have thought by Monza or shortly after Monza we should be clear."