Mercedes motorsport boss Toto Wolff is refusing to guarantee the German marque's Formula One future past 2020.
The manufacturer has been dominant since the 1.6 litre V6 hybrid formula was introduced in 2014, but that is no guarantee of the team's long term future once their current deal with F1 expires.
"Mercedes decided in 2009 to compete not only as an engine supplier but also with its own team in Formula One," Wolff told La Gazzetta dello Sport.
"We have committed ourselves until 2020, but what happens then is unclear. In my opinion, we will stay in formula one if the sport develops in a positive way," the Austrian added.
Mercedes' commitment to F1 is in the form of bi-lateral contractual agreements with the Bernie Ecclestone-led commercial rights holder, and are in the process of being taken over by Liberty Media.
Meanwhile, Wolff's contract with Mercedes, as well as that of team chairman Niki Lauda, is currently in the process of being renegotiated, although Wolff admitted that he may not stay in F1 for a long time.
"I came to Formula One as an investor with Williams," said the 44-year-old. "In 2012 I got this role at Mercedes. It's now 2016.
"I will not stay in formula one forever, let's say a few more years. As long as I am having fun at work.
"The situation is that I love what I do and I want to work with the same people with whom we have achieved such fabulous results," Wolff explained. "At the moment, I am negotiating for another two years.
"My work today is extremely intense and involves a great emotional commitment. When I'm no longer enjoying it, it's time to do something else."
Bahrain International Circuit - Winter testing