North Korea tested its new strategic cruise missiles for the second time in a week on Sunday, calling them newly developed submarine-launched cruise missiles (SLCM), in a move that accelerates its navy's nuclear armament, state media reported on Monday.

North Korean leader Kim Jong Un supervised the test of the missiles, called "Pulhwasal-3-31," which were identical to the strategic cruise missiles the North said last week were under development.

State news agency KCNA and the official Rodong Sinmun newspaper said the missiles flew above the sea off the country's east coast for 7,421 seconds and 7,445 seconds and hit an unspecified island target, indicating that their flight time exceeded two hours.