This year's calendar could yet include 20 grands prix after Bernie Ecclestone revealed that Portugal is vying for a place.
The Formula One circus was expected to stop at 20 venues this season, however, that number was cut when New Jersey delayed its inaugural race.
Turkey had initially been the favourite to fill the gap before talks broke down over the cost.
The calendar, though, may not yet to be reduced as Portugal's Autodromo Internacional do Algarve circuit is reportedly interested.
"Frankly, I do not know," Ecclestone told the Salzburger Nachrichten newspaper when asked about the matter.
"There is still interest from France for the race, and now Portugal with the Algarve circuit.
"For the German Grand Prix, the venue is still open."
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