Washington: A 37-year-old man has admitted in court that he ripped off a Muslim woman's hijab on board a flight in the US after screaming "Take it off! This is America!".

Gill Parker Payne of Gastonia, from North Carolina, pleaded guilty in a New Mexico federal court to a misdemeanour hate crime charge of using force to intentionally obstruct the woman's free exercise of her religious beliefs.

Near the end of his Southwest Airlines flight from Chicago to Albuquerque last December, Payne decided he had to take action.

Seated a few rows in front of him was a woman he had never met before. She was wearing a religious headscarf, known as a hijab, which Payne recognised as a Muslim practice.

He stood up, walked down the aisle and stopped next to her seat. Looking down at the woman, Payne instructed her to remove the covering, the Washington Post reported.

"Take it off! This is America!" Payne was quoted as telling the woman. When she did not do it herself, Payne grabbed the hijab from the back and pulled it all off.

Violated, the woman, identified by the Justice Department only as K A, quickly pulled the hijab back over her head.

As part of a plea deal with the federal government, Payne on Friday pleaded guilty to obstructing the woman's exercise of her religious beliefs.

"Because I forcibly removed K A's hijab, I admit that the United States can prove beyond a reasonable doubt that I intentionally obstructed K A's free exercise of her religious beliefs," he said in a written statement in the plea agreement.

Payne awaits sentencing. He faces a maximum penalty of one year in jail and a fine of up to USD 100,000.

"No matter one's faith, all Americans are entitled to peacefully exercise their religious beliefs free from discrimination and violence," Vanita Gupta, head of the Justice Department's civil rights division, was quoted as saying in a statement.

"Using or threatening force against individuals because of their religion is an affront to the fundamental values of this nation," she said.

FBI data show that hate crimes against nearly every group fell from 2004 to 2014. However, anti-Muslim hate crimes are the only exception, remaining nearly unchanged. There were 156 in 2004 and 154 in 2014.

The Bridge Initiative, a Georgetown University research project focused on Islamophobia, found in a report this month that anti-Muslim violence and vandalism rose last year from 154 to 174 reported incidents.

The 2015 incidents included 12 murders, 29 physical assaults, eight arsons, nine shootings or bombings, and 50 threats against people or institutions.