After more than 60 years, service members presumed killed in the Korean War arrived on U.S. soil Wednesday, their flag-draped caskets slowly filling a military hangar in Honolulu, Hawaii. But the government lab with the Defense POW/MIA Accounting Agency (DPAA), which accounts for Americans lost in conflict, faces a challenge, reports CBS News correspondent Vladimir Duthiers.

There was only one dog tag amid the 55 sets of remains, and when North Korea has returned remains in decades past, the bones of different people have reportedly been combined together or mixed with animal remains. Initial reports say the new remains appear to be in a similar state of disarray, meaning the identifying process could take years.

Still, many believe getting these service members back on U.S. soil brings them one step closer to their loved ones.

In March, we spoke with DPAA. Through lab analysis of artifacts, bones and DNA, the agency works to identify the soldiers and bring their families closure.

"When these guys went missing, it like created a big hole in their life," DPAA Laboratory director Dr. John E. Byrd said, adding, "What we're trying to do is fill that hole as much as we can."

Vice President Mike Pence and military honor guards met the 55 caskets at Joint Base Pearl Harbor-Hickam in Hawaii.

"Today begins a new season of hope for the families of our missing fallen," Pence said. "Hope that after so many years of questions, these families will have closure."

North Korean leader Kim Jong Un promised the return of the remains after his June summit with President Trump. Late Wednesday, the president tweeted, "Thank you to Chairman Kim Jong Un for keeping your word & starting the process of sending home the remains of our great and beloved missing fallen! I am not at all surprised that you took this kind action. Also, thank you for your nice letter - l look forward to seeing you soon!"

Thank you to Chairman Kim Jong Un for keeping your word & starting the process of sending home the remains of our great and beloved missing fallen! I am not at all surprised that you took this kind action. Also, thank you for your nice letter - l look forward to seeing you soon! — Donald J. Trump (@realDonaldTrump) August 2, 2018

"Some have called the Korean War 'the forgotten war.' But today, we prove these heroes were never forgotten," Pence said.