The 2009 champion still does not have a signed contract for next year, although both sides have made clear they want to continue together and Button has said he intends to see out his F1 career there.
Talks have focused on the length of the extension with Button thinking well beyond next year, when McLaren will still be powered by Mercedes and a new V6 engine is introduced in a major shake-up of the rules.
"I want to be here in 2015. That is an important year, I think," the 33-year-old told reporters ahead of an Italian Grand Prix at which the team will celebrate the 50th anniversary of their founding by New Zealander Bruce McLaren.
"I've worked for many years with that Japanese engine manufacturer, it will be exciting to work with them again in the future."
Button spent six years in Honda-powered cars, first with the BAR outfit that became the Honda team, and secured his first victory in Formula One with them in Hungary in 2006.
McLaren were at their most dominant with Alain Prost and Ayrton Senna in Honda-powered cars in 1988 and 1989.
The Monaco-based Button has a Japanese girlfriend and regards Tokyo as a home from home.
Although he has been linked in media speculation to Ferrari, where Brazilian Felipe Massa's place is under renewed scrutiny, Button left no doubt that his loyalties were firmly with McLaren despite a tough season.
The team have finished no higher than fifth in 11 races so far and a podium place, let alone a victory, looks a tall order even if it cannot be ruled out.
"I am loyal. In the past sometimes I haven't been," agreed the Briton.
"I think if you are with a smaller team that you can't see a future with, it's the right thing to always look for something better. But when you are with a team like this with the future that this team has, this is a very exciting opportunity for any driver.
"I know that Red Bull have had a great run for the last few years but it will stop," added Button. "I think when you are in a top team, any of the three or four top teams, it's better to stay put for the near future. But especially for me because I really do feel happy here."
Button, who will be the second oldest driver in the sport next season after Finland's Kimi Raikkonen, expected McLaren to come back strongly in 2014.
"I am really excited about 2015 but first of all we've got to look to next year and I think we can win the world championship next year with Mercedes-Benz," he said.
"There's still a very good partnership there with them and it will be nice to go out on a high."
Button has finished second three times at Monza but that sort of result can hardly be hoped for now and in any case a podium finish would not redeem the season for a team more used to winning.
Despite that, the Briton has not completely ruled out a return to the most hostile podium in the sport this weekend, with the partisan and passionate Monza crowd regularly booing those who are not wearing Ferrari red.
"It can happen. But we need wet weather, we need everything on our side to make it happen. We are not quick enough, our outright speed is not there," he said.
"You have those three teams (Red Bull, Mercedes and Ferrari) that are still fighting for the world championship, they are going to be pushing all the way to the end of the season whereas for us we're concentrating more on next year's car.
"There are parts that will be on this year's car that will also help us next year but we are not designing certain parts for this year's car that will be useless next year. We are limiting how much we will move forward this season."