A doctor has admitted assaulting a sleeping girl on a flight from Seattle to New Jersey's Newark Liberty International Airport this summer.

Vijaykumar Krishnappa appeared before a federal magistrate in Newark on Wednesday.

Prosecutors say the 29-year-old physician intentionally touched the girl near her groin over her leggings without her consent. She was sleeping in the seat next to him on the July flight.

Under terms of a plea agreement, the Indian national will be sentenced to between 30 and 90 days in prison in January.

He was studying medicine in the U.S. under a fellowship for doctors from foreign counties.