North Korea may have fired a ballistic missile from a submarine, according to officials in South Korea.
The missile is thought to have been launched near the port of Wonsan and flown about 450km before landing in the Sea of Japan.
The South Korean military said it reached an altitude of 910km.
The launch comes hours after Pyongyang said denuclearisation talks with the US would finally resume on Friday.
The National Security Council told South Korea’s Yonhap news agency that it is placing “weight on the possibility” that it was a submarine launched ballistic missile.
The first reports came in the early hours of the morning when authorities reported that two missiles were launched, with at least one landing in Japanese waters.