Queen admit they have a 'finite window of opportunity' for working with Adam Lambert

Queen guitarist Brian May has admitted that they have a "finite window of opportunity" when it comes to working with Adam Lambert.

The two parties have teamed up this year to tour regions like North America and Australia, with UK and Europe dates planned for early 2015.

May took to his official website on Monday (October 6) to post his response to a letter sent by Queen's Mexican fan club.

He admitted that the group only have a limited amount of time available to perform with Lambert, meaning they can't get to a number of countries.

He said: "First of all, I can tell you we haven’t forgotten Mexico. And we never will! And it would be great to come there and play...of that there is no doubt. But it’s only possible to do one thing at a time. And our lives are very full, and we are not as young as we used to be!For now we will put in as many dates as we can in as many of the Queen-friendly cities as we can, commensurate with still having a semblance of home life and balance in the Autumn of our years.

"The dates depend on someone in each city coming up with a suitable offer to promote the shows in a venue suitable for our present production. But also, of course we may have only a finite window of opportunity as far as working with Adam Lambert. And, physically, there are limits to what anyone can take on in any one period. Life is what it is! It will never be perfect, and it’s never possible to please everyone! But we will do the best we can. In the meantime, again...we won’t forget you."

Lambert meanwhile has been busy this year juggling his Queen duties with work on his upcoming third album.

Watch Queen perform with Adam Lambert below: