Bernie Ecclestone has promised to do everything he can to ensure HRT makes it to the end of the season but has concerns it might have to pull out.

HRT was born from the ashes of the financially struggling Campos Meta team, just four weeks before the start of the season. After attending the first five races it had appeared to find its feet in Formula One - albeit six seconds off the pace - but Ecclestone says he still has concerns.

"HRT have got problems," he told the Daily Telegraph. "I will sort it out. I'd like to see 12 teams finish the season because they have made the commitment to come in. We might lose one of them. But I'm doing my bit to make sure it doesn't happen."

He also revealed that races in Sochi (Russia) and Rome (Italy) were still on the cards and should appear on the calendar in 2013. Negotiations have been ongoing with both venues this season but Ecclestone insists the ball is still in his court.

"The Russians are good people," he said in the same interview. "They get on with things. It is a matter of whether it suits us or not. I have to have a look at it first. Rome is moving forward. That is going to be good. It's a bit political, obviously. But Rome could be ready in 2013 and Russia about the same time."