Airman Harpreetinder Singh Bajwa is a crew chief at McChord Air Force Base, Washington

A Sikh airman has been allowed by the United States Air Force to serve with a beard, turban and unshorn hair, making him the first active-duty airman to be granted such a religious accommodation.

Airman Harpreetinder Singh Bajwa, who joined the US Air Force in 2017, was unable to follow the practice due to the military branch's grooming and dress codes.

The Air Force granted him an accommodation after Mr Bajwa gained representation from the Sikh American Veterans Alliance, and the American Civil Liberties Union (ACLU), NBC news reported.

Harpreetinder Singh Bajwa, a crew chief at McChord Air Force Base, Washington, is now the first active airman who has been authorised to adhere to Sikh religious grooming and dress principles while serving in the Air Force.

"I'm overjoyed that the Air Force has granted my religious accommodation," said Mr Bajwa.

"Today, I feel that my country has embraced my Sikh heritage, and I will be forever grateful for this opportunity," he added.

Harpreetinder Singh Bajwa says he initially asked if he could request a waiver during tech training a year ago in Charleston, South Carolina, and said he was never told "no" by leadership.

"I'm extremely happy I can practice my faith and serve my country," said Mr Bajwa.

A first-generation American, Harpreetinder Singh Bajwa was born to an immigrant family.

In 2016, Captain Simratpal Singh, a decorated Sikh-American officer and combat veteran, received a long-term religious accommodation from the US Army to serve with long hair, a beard, and turban. The Army updated its regulations the following year directing commanders to allow accommodations for observant Sikhs.

Heather L Weaver, a senior staff attorney for the ACLU, praised the Air Force's decision.

"No one should have to choose between following their faith or serving their country," Ms Weaver said.

"We're pleased that the Air Force granted our client's request, and we hope that all branches of the military come to recognize the importance of religious inclusion and diversity."

