Earlier, there were also reports of construction delays, while German Tilke, whose company is responsible for the design of new F1 circuits, expressed concerns about the quality of the local construction contractors.
But Tilke has now told Russia's Championat he is "100 per cent certain" the circuit, part of the infrastructure for the 2014 winter olympics, will be ready on time.
"Nothing else is in my area of responsibility," he said.
"The track will be built on schedule," Tilke added, insisting that even the construction delay between November and the end of the 2014 games in February will not pose a problem.
"No, everything will be ok," he said. "The track will be ready on time."
Tilke also insisted he is no longer worried about the quality of the construction work. "All of these problems were long ago. Everything is now solved," he said.