WASHINGTON — The U.S. military is loosening its hairstyle requirements to allow more styles that are popular with black women, responding to criticism from some servicemen and lawmakers that black recruits had been treated unfairly by new restrictions.

Defense Secretary Chuck Hagel, in a letter this week to the chairman of the Congressional Black Caucus, wrote that all the military branches except the Marine Corps would expand their definitions of acceptable hairstyles to include cornrows, braids and other common black hairstyles.

Hagel also said military regulations in all branches would eliminate “offensive language, including the terms ‘matted and unkempt,’ from both the Army and Air Force grooming regulations.”

In April, Hagel ordered the secretaries of each military branch to conduct a policy review after the 16 women of the Congressional Black Caucus complained about new Army regulations banning large cornrows, twists and dreadlocks.

“As a result of these reviews, the Army, Navy and Air Force determined changes were necessary to their service grooming requirements to include additional authorized hairstyles,” Hagel wrote.