Fernando Alonso says McLaren contacted him about a return to the team over a year ago, with the squad's determination to sign him a key factor in his move from Ferrari.
After several months of speculation Alonso was confirmed as a McLaren driver for 2015 on Thursday, with the Spaniard lining up alongside fellow World Champion Jenson Button.
"I am joining this project with enormous enthusiasm and determination, knowing that it may require some time to achieve the results we are aiming for, which is no problem for me," said Alonso.
"Over the past year I have received several offers, some of them really tempting, given the current performance of some of the teams that showed interest.
"But, more than a year ago, McLaren-Honda contacted me and asked me to take part, in a very active way, in the return of their partnership – a partnership that dominated the Formula 1 scene for so long.
"McLaren-Honda's repeated and open desire, perseverance and determination in making it possible for me to join their exciting renewed partnership, have been some of the main factors that made me take this decision, not forgetting the most important factor of all: we share a common objective and expectations, and there is a very solid future, with confidence, ahead.
"I want to thank the persistence of those who have fought so hard for this to come true. I will do everything in my power to deliver for everyone and for our team, based on a formula that has always worked for me: effort, sacrifice, perseverance and faith."
Alonso previously raced for McLaren in 2007, when he racked up four wins and placed third in the Drivers' Championship prior to departing at the end of the year after falling out with the team.