The Pentagon agency in charge of accounting for missing Americans troops has yet to receive notice to prepare for the return of remains by North Korea that President Donald Trump called a key success of the Singapore summit.

"We're standing by [but] we haven't officially been asked to do anything," Chuck Prichard, a spokesman for the Defense POW/MIA Accounting Agency (DPAA), said Monday.

"This is our business," he said of recovering remains from foreign battlefields. But he added that the work of diplomacy must come first. "We're at the tail end of this."

On the North Lawn of the White House last Friday, Trump suggested to Fox News that the remains of missing Americans from the Korean War might already be in the process of being repatriated.

He said the North Koreans "are already starting to produce the remains of these great young soldiers who were left in North Korea. We're getting the remains, and nobody thought that was possible."

At the Singapore summit last Tuesday, Trump and North Korean leader Kim Jong Un signed a joint declaration committing to sending the missing troops home.

"The United States and the [Democratic People's Republic of Korea] commit to recovering POW/MIA remains, including the immediate repatriation of those already identified," the declaration reads.

At a news conference after the summit, Trump said he was acting on behalf of the families of the missing.

"I must have had just countless calls and letters and tweets, anything you can do -- they want the remains of their sons back," Trump said.

It's unclear, however, how many parents of troops killed in a war that ended with an armistice 65 years ago might still be living.

"I asked for it today, and we got it. That was a very last minute," Trump said of the agreement. "The remains will be coming back. They're going to start that process immediately."

Richard Downes, executive director of the Coalition of Families of Korean & Cold War POW/MIAs, told Military.com by email last week that North Korea may already have about 200 sets of remains ready to be returned.

Downes, whose airman father Lt. Hal Downes is still listed as missing from a flight over North Korea in 1952, said he learned of the possibility that the North has 200 sets of remains on a visit to Pyongyang in 2016 with the Richardson Center for Global Engagement.

During the visit, Downes said he had received an offer from North Korea's vice foreign minister regarding his father's remains.

"We took it to the Obama administration but were refused," Downes said. "They preferred to hold out until NK responded to the nuclear issue. It was heartbreaking."

Downes praised Trump for being "the first to make the leap" on the recovery of remains.

"A lot of people/organizations worked to get it on the summit's agenda," he said.

According to DPAA, more than 7,800 Americans have not been accounted for from the Korean War.

-- Richard Sisk can be reached at Richard.Sisk@Military.com.