Martin Whitmarsh has refused to comment on reports that McLaren let their engine option with Mercedes lapse admits rumours of Honda's return.
According to Germany's Auto Motor und Sport, "the team from Woking had until the end of April to decide whether to also use Mercedes in 2015."
The report added that sources have reported that "this period has elapsed."
This has raised suggestions that McLaren could be looking to Honda to supply them with 1.6-litre V6 engines for next season.
Whitmarsh, though, isn't saying which way McLaren are leaning.
"The discussions about '15 are between myself and Mercedes and not for newspapers," he told Sky Sports F1.
Pressed as to when he might inform the public of his decision, Whitmarsh added: "Certainly before 2015 - I'll promise I'll tell you before then!"
The announcement, though, could come sooner rather than later as AFP are reporting that Honda could announce their return to Formula One as early as this week.
According to a source, Honda president Takanobu Ito will confirm that the Japanese manufacturer will supply engines to McLaren from 2015.
"Honda has not officially denied these reports," said the source. "Please prepare yourself for the announcement."
Honda's last involvement in F1 ended in 2008 when they sold their F1 team to Ross Brawn. Brawn went on to win the 2009 title double before selling to Mercedes.