Mercedes will remain McLaren's engine partner for the next three years, according to the Woking squad's team principal Martin Whitmarsh.
The German manufacturer has been supplying McLaren with power units since 1995 and the two parties signed a new agreement in 2009 that will see the partnership continuing until at least 2015.
However, reports suggest McLaren are looking for a new supplier and Honda - who are set to return to Formula One following their withdrawal from the sport after the 2008 season - has been named as the firm favourite to take over.
According to German media, the only "question is whether the Japanese manufacturer is coming in 2014 or wait until 2015" while BBC Sport claims that 'McLaren are first expected to race with Honda engines in 2015'.
Whitmarsh, though, says they are committed to seeing out their current contract with Mercedes.
"What I can tell you is we have a contract with a long-standing partner, Mercedes-Benz, for 2013, 2014 and 2015," he said in an interview with Sky Sports F1.
"So we have a contract, they're our partners and we're going to try and win World Championships and races with them."
Formula One will move from 2.4-litre V8 engines to 1.6-litre turbos in 2014 and several car manufacturers have shown an interest, which can only be good for the sport according to Whitmarsh.
"There's a lot of speculation and I've heard Porsche, Hyundai, Honda, all those sorts of names," he said.
"I hope for Formula 1 that these manufacturers come back - we need them in the sport. At the moment we've got Renault, Mercedes, Ferrari; we need more engine suppliers."
As for McLaren's long-term future, Whitmarsh added: "We've got a good and long-standing commitment to Mercedes-Benz, that's what we're focused on right now
"In the longer term who knows what's going to happen? We're delighted to be partnering Mercedes-Benz. They've done, certainly in the last few years, a fantastic job and we've won a lot of races together and we're going to try and win quite a few more in the next few years."