Honda is hoping to up the power of its engine over the coming races in order to ease the growing pressure on McLaren to perform.

The new McLaren-Honda partnership has scored just four points this year after suffering from persistent reliability issues, including a double retirement at the last round in Canada. The Canadian Grand Prix also exposed the power deficit between Honda and its rivals, with the McLarens as much as 35km/h slower than the quickest cars on the straights while struggling with fuel efficiency in the race.

Honda spent two of its power unit development tokens ahead of the Canadian Grand Prix and boss Yasuhisa Arai says there is more to come.

"On the power unit side, we will see more horsepower in the near future by using the tokens and step-by-step up the horsepower in the next few races," he said. "We are working very hard as one team, not only on the power unit but also aerodynamics and chassis.

"We have seen good progress in those two areas [aerodynamics and chassis] between Australia and Canada and maybe in a few more and in the second half of the season we can achieve top level performance and compete with the top level teams."

Racing director Eric Boullier admits pressure is mounting on the team, but says the McLaren board still trusts in the work it is doing.

"There is pressure, it's normal," Boullier said. "We are all competitors and we want to win and be competitive, so there is pressure on Honda, McLaren and our shoulders.

"Like any company in the world they [the board] come to visit us, which is good support, and they are here also to understand. We have a duty to report, which is normal, but we don't have an extraordinary pressure. We are transparent enough for them to know what we are doing and we hope that we know what we are doing as well."

Boullier said both power unit and chassis were currently lacking compared to the best in F1.

"If you want to win, you have to be the best everywhere. In terms of aerodynamics, vehicle dynamics, chassis, power unit and drivability - we have to improve everywhere. We are lacking in downforce to be the top chassis, so we have to work on this and make it better. It's a new concept, a new philosophy this year and on the Honda side there is of course more work to be done in terms of performance."