Alonso will "talk to anyone" to have winning car in 2018

The two-time champion's current contract with the Woking-based outfit comes to an end at the end of this year, and he has made it clear he wants to have a competitive car as soon as possible.

Alonso rejoined McLaren in 2015, but has endured a disappointing spell so far as the Honda engine has failed to deliver what the team expected.

The Spanish driver insisted his priority is to remain in F1, but warned that he may look elsewhere if McLaren-Honda has not made enough progress soon.

"I like this F1. My intention or first priority is to race here," said Alonso ahead of the Spanish Grand Prix. "I am happy with the team but we are not winning.

"If from here to September/October we are in a position where we see clearly a possibility to win in 2018, I will be more than happy to stay with the team.

"If it is not the case then I will be more than happy to talk to anyone," he added.

Alonso, who will miss the Monaco F1 race later this month to compete in the Indianapolis 500, said that he is likely to make a decision about his future after the summer.

"I will have to think a little bit after the summer as now it's not an easy period and with the Indy 500 thing will be difficult to think about something else," he said.

"Around the summer I need to consider what I will do next year and if it is time to find other challenges outside F1 or if in F1 there will be an opportunity to win the championship which is my main goal.

"I am very open to anything."

The McLaren driver, who failed to start the previous race in Russia after yet another engine problem, reiterated his belief that Honda's reliability has been "unacceptable" so far.

Speaking about reliability, he said: "We need to raise our game and hopefully finish with both cars this weekend.

"We have been underperforming in the first four races and we didn't finish any of the GPs yet, in my case.

"Not being able to start the race with Stoffel's car in Bahrain with my side of the garage in Russia, completely unacceptable. We need to raise our game here in terms of reliability and hopefully finish with both cars.

"Hopefully this is the start of a new championship for us."

Additional reporting by Jonathan Noble