The missile, believed to be a type of Pukguksong, a North Korean SLBM, was fired from off the east coast near Wonsan in an easterly direction at 7:11 a.m., and flew around 450 kilometers at a maximum altitude of about 910 km, according to the Joint Chiefs of Staff (JCS), reported South Korea's Yonhap news agency.

"Our military is monitoring the situation in case of additional launches and maintaining a readiness posture," the JCS told the South Korean news acgency, calling on the North to stop such acts that heighten tensions on the Korean Peninsula.

Just hours earlier, Pyongyang had said denuclearisation talks with Washington could finally resume later this week, BBC reported.

Meanwhile, negotiations between North Korea and the US have been stalled ever since the Hanoi summit between US President Donald Trump and North Korean leader Kim Jong-un in February ended without an agreement.