WASHINGTON — The Navy said Tuesday that it is evaluating whether sailors aboard the USS Wasp violated Defense Department policy by sporting unofficial uniform patches with the phrase “Make Aircrew Great Again” during a Memorial Day visit by President Donald Trump.

The red, circular patch featured a finger-pointing cartoon figure similar in appearance to Trump with words reminiscent of his famous campaign slogan “Make America Great Again.” Photographs of several Navy airmen aboard the warship in Japan wearing the patches circulated Tuesday on Twitter, where they were first posted by a Wall Street Journal reporter traveling with the president.

“Navy leadership is currently reviewing this instance to ensure that the wearing of the patch does not violate DOD policy or regulations,” Lt. Samuel Boyle, a Navy spokesman at the Pentagon, wrote in a single-sentence email Tuesday afternoon.

Troops across the military services have long worn unofficial insignia, known as morale patches. Often boasting humorous themes, the patches are widely available for purchase online and in military supply stores. Though such patches are officially barred by uniform regulations, they can be approved by troops’ chains of command.

It was not clear Tuesday whether the “Make Aircrew Great Again” patches had been approved by the sailors’ commanders. It was also unclear where the sailors had obtained the patches.

Monday was not the first time that the patches have made an appearance on the uniform sleeves of Navy airmen. A helicopter crew chief was photographed by Stars and Stripes in July 2018 wearing the same patch at Barking Sands Missile Range in Hawaii during Rim of the Pacific naval exercises. The Pentagon, itself, shared a photo on social media of a sailor wearing the same patch in 2017.

On Twitter, former top military officers said the patches could be problematic because they could be interpreted as the military institution supporting a civilian politician.

“DOD has a longstanding policy of encouraging military personnel to carry out the obligations of citizenship,” an explanation of Pentagon regulations states. “However, [active-duty] members will not engage in partisan political activities and all military personnel will avoid the inference that their political activities imply or appear to imply DOD sponsorship, approval or endorsement of a political candidate, campaign or cause.”

Marine Gen. Joseph Dunford, the chairman of the Joint Chiefs of Staff, in recent years has routinely reminded servicemembers that the military is an apolitical institution and their sworn oath is to the U.S. Constitution and not to a politician or political party. Additionally, troops are barred from publicly supporting any candidates for office – including the presidency – or conducting other political activity while in uniform, by the 1939 Hatch Act.

Retired Army Lt. Gen. Mark Hertling, who commanded troops in Iraq and Europe before retiring in 2012, wrote on Twitter that the patches were “inappropriate [and] against regulation.”

He later shared anecdotes of instances overseas where he approved soldiers wearing unofficial morale patches, including his wearing of patches depicting the Iraqi flag while commanding there and the nation of Georgia’s flag, while working with troops in that country.

“When patrolling with our Iraqi counterparts, I put a Velcroed Iraqi flag on the shoulder opposite the U.S. flag, to show them we were fighting together,” Hertling wrote. “That’s also ‘unauthorized’ but I got permission from my [four]-star boss.”

Trump visited Monday with Navy sailors and Marines aboard the Wasp, an amphibious assault ship capable of carrying Marine Corps F-35B fighter jets, at Yokosuka Naval Base near the end of his Memorial Day weekend visit to Japan.

Troops on other occasions have drawn attention for their actions during presidential visits, including in December when the president was observed autographing red “Make America Great Again” ball caps for Air Force personnel at Ramstein Air Base in Germany.

Following a short investigation, the Air Force determined the troops had not violated rules or regulations and had not worn the hats with Trump’s campaign slogan while in uniform.

“There is no rule against airmen bringing personal items to be signed by the president,” U.S. Air Forces Europe said in a statement at the time.

dicksten.corey@stripes.com

Twitter: @CDicksteinDC