Preparations are underway at Joint Base Pearl Harbor-Hickam for the Wednesday repatriation to U.S. soil of presumed American remains from the Korean War turned over by North Korea.

Two Air Force C-17 cargo aircraft will be parked back to back outside Hangar 19 as 55 American-flag-draped aluminum transfer cases are carried off the planes by two joint service honor guard details. Vice President Mike Pence will speak at the 2 p.m. ceremony.

The remains will then be transferred to the Defense POW/MIA Accounting Agency’s lab on Hickam for identification — a process that could take several years or longer.

Korean War veteran Herb Schreiner, 88, who served in 1952-53 at Kimpo Air Base keeping F-86 Sabre jets flying, will attend the ceremony.

“I feel very close to it because I know how it feels” to lose a family member, the Pearl City resident said.

Schreiner’s brother, Alan, was 17 when he stepped on a land mine and was killed in Korea.

“My mother signed for him to go in,” he said. “He begged her, and she took that to the grave.”

But Schreiner, president of the Korean War Veterans Association, Hawaii Chapter 1, said his family had closure. His brother was buried at Punchbowl cemetery.

“But I look at this (return ceremony) and say, too bad the fathers, mothers, the husbands and children are not able to grieve them — because we don’t know who they are,” he said. “The remains have to go through DNA (testing).”

In a statement, Pence said President Donald Trump asked him to participate in the “honorable carry ceremony” and receive the presumed American remains as they return home.

“We will never forget the sacrifices these brave service members and their families made for our nation and our freedoms,” Pence said.

Fourteen Hawaii residents who are Korean War veterans are expected to attend the ceremony, along with dozens of others from the Vietnam War and veterans organizations such as the American Legion, Military Order of the Purple Heart, Special Forces Association and Veterans of Foreign Wars.

A C-17 containing remains of fallen service members departed Wonsan, North Korea, on Thursday Hawaii time headed to South Korea.

Defense Secretary James Mattis told reporters Friday that once in the South, the accounting agency would “look for any anomalies,” and “then the forensics will begin when we land them in Hawaii where the laboratory is.”

“We don’t know who’s in those boxes,” Mattis said, adding they could be missing Americans or Australian or French troops.

On multiple occasions in the past, North Korean officials claimed the government possessed as many as 200 sets of American remains that had been recovered over the years, the accounting agency said.

Mattis said it was a “good question” as to why 55 sets of remains are coming home.

“We can’t go back in and verify what the number they had was before,” he said. “We know what they said. But for us we’ll simply say this is obviously a gesture of carrying forward what they agreed to in Singapore, and we take it as such.”

President Donald Trump met with North Korean leader Kim Jong Un on June 12 in Singapore. North Korea committed “to work toward complete denuclearization of the Korean Peninsula,” and both countries vowed to recover POW/MIA remains.

Mattis said the repatriation is the “first step of a restarted process” to recover American remains from North Korea.

The last time North Korea turned over American remains was in 2007. Six boxes were given to a delegation headed by then-New Mexico Gov. Bill Richardson on a trip to the North.

One of those service members was identified in 2012 for return to family.

Army Cpl. Patrick Glennon, 18, with the 1st Cavalry Division, was among soldiers holding a defensive position on Nov. 1, 1950, near Unsan, North Korea, when they were attacked by Chinese forces.

Following heavy fighting, Glennon was listed as missing. Identification tags with his name were included with the remains turnover.

Scientists at the Hickam lab and the Armed Forces DNA Identification Laboratory used circumstantial evidence and forensic tools including dental records and mitochondrial DNA — which matched his cousins — to make an identification.