London, May 17 (IANS) Prince Philip, the husband of Queen Elizabeth, who would soon turn 90, still feels disappointed at deserting a promising naval career after his wife became the British monarch in 1952.

The Duke of Edinburgh said in an ITV1 interview that he regrets at making many "mistakes" in his 90-year-long life, the Daily Express reported.

"Well, I mean, how long is a piece of string? I don't know how difficult it was, it was naturally disappointing. I had just been promoted to Commander and the fact was that the most interesting part of my naval career was just starting," he said.

"But then, equally, if I stopped and thought about it, being married to the queen, it seemed to me my first duty was to serve her in the best way I could."

Philip, who celebrates his landmark birthday June 10, also earned a bad reputation for making controversial comments.

During a visit to China in 1986, he reportedly described Beijing as a "ghastly" place and told British students: "If you stay here much longer you'll all be slitty-eyed."

He reportedly once asked a Scottish driving instructor: "How do you keep the natives off the booze long enough to pass the test?"

On hearing singer Tom Jones perform at a Royal Variety Performance, the prince asked: "What do you gargle with, pebbles?"

Philip - who also marks 59 years as the queen's consort - was, however, tight-lipped on details about the "mistakes" he made.

"Well yes, I would rather have not made the mistakes I did make, but I'm not telling you what they were."

Buckingham Palace said that on June 12 a special service will be attended by the queen and other members of the royal family to mark his birthday.