Sao Paulo, April 16 (IANS): Formula One chief Bernie Ecclestone says Sao Paulo could be taken off the calendar if the city fails to improve facilities at its Interlagos Grand Prix circuit.

The F1 chief has given local officials an ultimatum to upgrade commercial boxes, event rooms and sanitary areas in addition to the paddock and pit-lane areas, reports Xinhua.

"The design of the circuit is among the best in the world, but the facilities for the teams and fans are the worst on the calendar," Ecclestone told local media Monday.

"We can't put pressure on other venues to improve when Interlagos is the way it is. The other circuits know what Interlagos is like and for that reason it puts us in a difficult position."

Ecclestone said Rio de Janeiro and the resort city of Penha in Brazil's southern state of Santa Catarina could host future races should Sao Paulo fail to meet F1's demands by next year.

Interlagos, which is contracted to host an annual Grand Prix until 2015, was Brazil's first F1 home in the 1970s before losing its host status to Rio de Janeiro's Jacarepagua circuit in 1981. The event returned to Interlagos in 1990 and has remained there since.