McLaren CEO Zak Brown has revealed he is "slowly reviewing" a potential engine supplier change ahead of 2026.
The Woking-based team is in partnership with Mercedes having left Honda and Renault at the end of last decade.
But ahead of the new-for-2026 engine regulations, the FIA confirmed six manufacturers have registered interest in supplying power units.
READ MORE: Wolff reveals Mercedes 'change of approach' after W13 vow
With five of those OEMs already confirmed to be taking to the grid [Alpine-Renault, Red Bull-Ford, Ferrari, Mercedes and Audi], the inclusion of Japanese manufacturer Honda raised eyebrows.
Honda's route back into F1 seemed to have been cut off by Red Bull's partnership with Ford, although there is the potential for one of the remaining 'supplied teams' on the grid to take up a works offer.
McLaren 'happy with Mercedes'
On whether McLaren was assessing its potential opportunities, Brown replied: "We are very happy with Mercedes.
"We have some time to decide on what we want to do in 2026 and beyond, it is an exciting time for F1.
"To have as many manufacturers coming into the sport, I think it shows the growth and the excitement.
"It is something Andrea and I are in the process of slowly reviewing, we are in no great rush and very happy with Mercedes.
"So we will see how things play out in the next year or so before we need to make a decision."
READ MORE: Webber delivers verdict on 2023 F1 title contenders