Police are seeking the public's help to find a missing 15-year-old girl from Neptune.

Payton Cox, who attends school at Red Bank Catholic, left her home on Sunday and hasn’t been seen by her family since then.

She was last spotted on video surveillance in New York City on Tuesday.

Monmouth County prosecutor Raymond Santiago says that she boarded a train in Long Branch on Sunday night, headed for New York City.

The prosecutor considers her to be a runaway, telling News 12 New Jersey that investigators have learned she was planning to meet someone.

“I can confirm at least her intentions were to meet up with an individual,” said Santiago. “I wouldn’t go into detail at this juncture, but it is an individual we located and we are continuing our investigation.”

The prosecutor would not say if that person, who remains unidentified, was another teen or an adult.

Payton Cox is described as 5 feet, 8 inches tall, and was last seen wearing black and red checkered flannel pajamas, a white hoodie and a dark jacket. She also left home with a black backpack.

While her family in Neptune is not speaking out, there is a missing person photo of the teen on a utility pole about a block from their home.

Neptune Police Chief Anthony Gualario says Payton’s family and friends are very concerned for her well-being.

“We want her to know if she’s watching this to please reach out even if you call 911 or maybe you call a family member or a friend. Just let us know that you’re OK," he says.

The Trenton Diocese, which oversees Red Bank Catholic, has declined comment.

The FBI, state police and NYPD are all involved in the search. Anyone who sees her is asked to contact police.