Toto Wolff says that Mercedes is unwilling to "interfere" in McLaren-Honda's current relationship amid speculation that it could be set to power the British team from 2018.

McLaren ended a two-decade partnership with Mercedes at the end of 2014 in order to pick up an exclusive Honda power unit supply from 2015, only for its fortunes on-track to nosedive as a result.

Relations between McLaren and Honda appear to be at breaking point as the team sits at the foot of the constructors' championship, with a split possible at the end of the year.

Should McLaren cut ties with Honda, it has been linked to a Mercedes engine deal that would possibly see the German marque power four teams on the grid.

Mercedes F1 chief Wolff was coy about the speculation, though, saying he did not want to interfere in relations between McLaren and Honda, with the latter's continued involvement in the sport being a key priority.

"There's quite some momentum in the market at the moment, which we watch from the sidelines," Wolff said at the FIA Sport Conference in Geneva on Tuesday.

"This is a position we have put ourselves in because the most important thing is that Honda performs, stays in the sport and has a good deal with its customer teams or works teams.

"We wouldn't want to interfere at that stage, that is our priority."

When directly asked if Mercedes would be open to supplying McLaren next year, Wolff said: "This is not our priority at the moment. First we would like to see Honda and McLaren sorting out their relationship.

"The main priority is for Honda to stay in the sport and for Honda to have a functioning relationship with its customers. That's why at the moment we do not wish to dive into this topic."

Besides its own works operation, Mercedes also supplies engines to Force India and Williams in 2017.