Honda has informed the FIA that McLaren is the only Formula 1 team with which it has an engine supply contract for 2017.
Under new rules, the manufacturers had until Sunday to submit a letter to the FIA outlining the supply deals they had in place.
If any team is left without an power unit for next season, the FIA will then begin talks to find a solution.
Should that not happen before the next deadline of June 1, then a ballot will be organised to arrange a supply.
Honda has had conversations with teams about a potential second supply, but there have been no formal talks.
Its chief Yusuke Hasegawa has said it is not currently ready to supply a second team alongside McLaren but is open to doing so in the future.
Although Honda can have talks with other teams about a supply, it is believed McLaren has the right to veto if it feels any such deal is not in its interests.
Two of F1's other three engine manufacturers have already moved to confirm their 2017 plans ahead of the deadline.
Renault has said it is happy to continue to working with Red Bull beyond this season once its current contract expires.
Meanwhile, Mercedes has told the FIA it has contracts in place with Williams, Force India and Manor.