Sochi may alternate a single Russian GP date on future F1 calendars with a new venue in St Petersburg.

Hermann Tilke, the designer of the St Petersburg venue called Igora Drive, recently said it will be "certainly capable of hosting Formula 1".

So when asked about rumours Liberty Media wants to expand the future F1 calendar from 22 to up to 25 races, Sochi promoter Sergey Vorobyov said that would be "difficult".

"It will be difficult for teams to cope with 25 grands prix per season," said Vorobyov, who heads the race promoter Rosgonki.

"But I do think expanding the calendar is inevitable. Formula 1 wants another race in the United States, the home market, plus South Africa and Asia.

"There will not be another race in Russia - not immediately. When Igora Drive receives the status of a F1 circuit, it is possible to alternate with Sochi or even have two races in a season, but not for at least 2-3 years," he told Forbes Russia.