United boss Sir Alex Ferguson confirmed earlier this week that they were planning to take up the one-year extension on Berbatov's contract.
The 30-year-old's future has been the subject of speculation as he has started just two Premier League games this season, but the Bulgarian admits he is happy to stay as he remains part of Ferguson's plans.
"There are always rumours about my future and some clubs are interested," Berbatov told The Sun.
"But last summer I was told by United that they need me - and that was good enough for me.
"As a professional I want to play in every game so I need to exploit all chances so no one can doubt my work."
Berbatov is determined to fight for his place in the United starting XI despite slipping down the pecking order this term.
"My worst moments are when I know the starting XI and I am not on the list," added Berbatov. "My objective in training is always clear - to give myself a chance of making the team.
"Obviously I want to play but it is very complicated in a squad as good as United's, especially in attack. But when I'm on the bench I am full of tension because at any moment the chance to play might arrive. I'm never relaxed.
"I think I have fulfilled my obligation with six goals this season set against the time I've actually spent on the field.
"But my challenge is to play, score goals and to help us get more victories."