Chase Carey has played down speculation that next year's 21-race calendar could actually drop to 19 grands prix.
Both China and the popular Singapore night race have been marked on the provisional 2018 schedule as "subject to commercial rights holder confirmation".
F1 CEO Carey said: "Our goal is to have the races in Shanghai and Singapore.
"We are negotiating new agreements that are not signed, but we have good communication and our expectation is that these races are on the calendar.
"We would not have put 21 races on the calendar if there are doubts, but the reality is that today we do not have agreements."
A spokesman for the Singapore Grand Prix confirmed that a decision about the 2018 street race "has not been reached".