Singapore wants to end its F1 grand prix contract after next year, Formula One boss Bernie Ecclestone said.
Ecclestone's comments hinted that negotiations had not gone well.
"Look at what we have done for Singapore," Ecclestone said. "Yes, the grand prix has cost Singapore a lot of money, but we've also given them a lot of money," he said. "Singapore was suddenly more than just an airport to fly to or from somewhere. Now they believe they have reached their goal and they do not want a grand prix anymore."
The Singapore race costs about S$150 million per year, with a majority of the funds coming from the city-state's government.
Ecclestone later said that F1 did not want to lose Singapore.
"My words were taken in a funny way. What I said was simple: No decision has been taken yet. Negotiations are ongoing and will be sorted out shortly… before the end of the year, I'm sure," he said.
"We want to extend long-term. We'll see what happens."
The sport has announced a provisional 21-race calendar for next year.
The Singapore race drew about 100,000 people on all three days in its first year, but the numbers have dropped, with an average of 87,000 per day last year and 73,000 this year.
Southeast Asia is in danger of not having the sport in the region after 2018 after Malaysia dumped its event — which has been held at Sepang since 1999 — also due to falling ticket sales and TV viewership, meaning the region would be without F1 for the first time since 1998.
Natixis SA economist Trinh Nguyen said that the attendance numbers might be because the novelty of F1 in the region is waning coupled with weak growth.
"It [F1] also comes with costs. Thus, with tourism receipts [from F1] waning, the cost-benefit calculus is tipping in the other direction," Nguyen said.