A registered sex offender who admitted that he improperly touched a sleeping woman aboard a flight from Israel to the U.S. has been sentenced to 13 months in prison.

Yoel Oberlander was sentenced in federal court in New Jersey on Thursday after pleading guilty in March to assault with intent to commit stalking.

Prosecutors say the groping occurred aboard an El Al flight from Tel Aviv to Newark Liberty airport in May 2016.

The victim was sitting next to Oberlander. The 36-year-old Monsey, New York, man admitted touching the woman's chest, upper thigh and hand without her consent and with the intent to harass and intimidate her.

Authorities have said Oberlander was convicted in 2002 in New York of sexually abusing an 11-year-old girl.