(Picture: Yahoo)

US and North Korean military officials met on the inter-Korean border on Sunday to discuss the return of remains of US soldiers killed in the 1950-53 Korean War, the first time in nine years that generals from the two sides have held talks, South Korea's Yonhap news agency said.

The repatriation of US remains was one of the agreements reached during an unprecedented summit between US President Donald Trump and North Korean leader Kim Jong-un in June in Singapore.

US Secretary of State Mike Pompeo unveiled the plan for talks after visiting Pyongyang this month, touting it as one of key issues on which the two sides had made progress, though the North accused his delegation of making "gangster-like" demands in connection with denuclearization during the trip.

Pompeo initially said the two sides had agreed to hold talks on US remains on Thursday but no North Korea representatives showed up on the border. North Korea then proposed meeting US military officials on Sunday, US and South Korean officials have said.

South Korea's Yonhap news agency, citing South Korean government and US military sources, said the negotiations had begun at 0100 GMT at the border village of Panmunjom in the Demilitarized Zone (DMZ) separating the two Koreas.

Three vehicles of US forces in South Korea, flying UN flags, were spotted heading to the border earlier in the day, Yonhap said.

Michael Minihan, an Air Force major general at US Forces Korea who doubles as chief of staff for the UN Command (UNC), was representing the US side and his counterpart is expected to be a military commander stationed in the DMZ, the news agency said.

A UNC official said he had no information to confirm the report, though preparations had been made for Sunday's talks. A US Embassy spokeswoman in Seoul was not available for comment. 

US forces brought some 100 wooden coffins into the DMZ last month, which will be used to transport the remains, according to Yonhap.