United Kingdom, May 24 -- Britney Spears has apologised for smoking onboard a plane.

The 43-year-old pop star has taken to social media to issue an apology, after she was recently reported to have smoked a cigarette and drank alcohol while on an plane.

Britney wrote on Instagram: "It's actually incredibly funny. Some planes I've been on you can't smoke mostly, but this one was different because the drinkholders were on the outside of the seat.

"Confession: It was my first time drinking VODKA!!! I swear I felt so SMART!!! [laughing emojis] I was like, 'Wow what the heck is in there.' I felt so clear and smart, and said, 'I want a cigarette so bad!!!'

"My friend put it in my mouth and lit... it up for me so I was like OH SO THIS IS A PL...