The remains of at least 22 Marines killed in the bloody 1943 Battle of Tarawa — a costly lesson in amphibious attack — were returned to American soil Wednesday night and honored in a ceremony at Joint Base Pearl Harbor-Hickam.

An Air Force C-17 cargo aircraft transported the Marines from the Republic of Kiribati 2,400 miles southwest of Hawaii.

Honor guards of six Marines wearing white gloves acted as pallbearers for each of 22 American flag-draped caskets that were carried into Hangar 19 at Hickam.

“Today we welcome home more than 20 American servicemen still unaccounted for from the Battle of Tarawa during World War II,” acting Secretary of Defense Richard Spencer said in a news release. “We do not forget those who gave the ultimate sacrifice, and it is our duty and obligation to return our missing home to their families and the nation.”

The Defense POW/MIA Accounting Agency will seek to make identifications of the fallen Marines at its lab at Hickam.

The Battle of Tarawa, waged from Nov. 20-23, 1943, was part of Operation Galvanic to capture Japanese-held territory in the Gilbert Islands. It was the first major seaborne assault launched against a heavily defended atoll — and the Marines paid a large price in lives for their ultimate success.

Over 76 hours, about 1,000 Marines and sailors were killed and more than 2,000 were wounded trying to take the heavily-defended Japanese outpost on the tiny isle of Betio, just a few miles long but bristling with dug-in troops, snipers and machine guns. Landing was made difficult by low tide and assault boats hung up on reefs.

Nearly all of the 4,800 Japanese defenders and Korean laborers were killed. The hard lessons learned would factor into every amphibious landing to come as the United States island-hopped across the Pacific.

The remains returned Wednesday are believed to belong to the 6th Marine Regiment, which fought hard taking out Japanese pillboxes and faced snipers and a “banzai” wave attack.

More than 150 Marines from Marine Corps Forces Pacific and service members with the accounting agency stood at attention as the caskets were brought in.

Lt. Gen. Lewis Craparotta, commander of Pacific Marines, said in remarks that, “As a Marine and perhaps for everyone who is present here tonight, it’s both an honor and a privilege as these Marines arrive back to the country that they loved.”

The Marines “gave their last measure so that we could live in peace,” he added.

Rear Adm. Jon Kreitz, deputy director of the accounting agency, said he was humbled to be there “to pay respects to these warriors who have finally begun their long-awaited journey home.”

Florida-based History Flight Inc., a nonprofit group, located the Marines and turned them over to the accounting agency in what the group said is the third largest recovery of missing Americans from Tarawa since major government repatriation work was finished in the 1950s.

History Flight turned over 24 sets of Tarawa remains in 2017, and 35 sets in 2015, including those of Medal of Honor recipient Marine Corps 1st Lt. Alexander Bonnyman Jr.

The group said that for many decades, few Americans were aware that over 500 Marines and a small number of Navy and Army personnel remained buried on or near Betio.

History Flight has a contract with the U.S. Defense Department worth $4.1 million for the recovery effort through July.

After the fighting, remains were hastily buried in trenches and other graves that were subsequently built over.

History Flight said it located over 100 individuals from in and around a site known as Cemetery 33. The latest recovery, which includes a total of more than 30 individuals, was partly underneath a building, said Executive Director Mark Noah.

The site was also below the water table.

“So the recovery work had to be done while pumping the local water table down to below the level that the burials are at, so it was very time-consuming,” Noah said in a phone interview.

“We’re very pleased to see the continued stream of successful recoveries from our partnership with DPAA,” Noah said.

The Associated Press contributed to this report.