A team of U.S. experts have joined an investigative team on the three suspected North Korean drones, recently found crashed in South Korea.
Citing an official from the defense ministry, Seoul-based Yonhap News Agency reports that several U.S. experts arrived in Seoul Monday, and were briefed on the interim investigation by South Korean officials.
The U.S. experts will attempt to find conclusive proof the drones were from North Korea.
Pyongyang on Monday said it was unreal and unscientific for Seoul to say the drones came from North Korea.
The North's National Defense Commission also suggested setting up a joint investigative team on the incident.
The three unmanned aerial vehicles were found in Paju, north of Seoul, on the western island of Baengnyeong-do Island, and in Samcheok, Gangwon-do province.