Seoul, Feb 15 (IANS): North Korean leader Kim Jong-un has supervised the test-firing of a new surface-to-sea missile and ordered a tighter defence posture near the western maritime border, Pyongyang's state media reported on Thursday.

North Korea test-launched the new missile, named Padasuri-6, on Wednesday, Yonhap news agency reported, citing the Korean Central News Agency (KCNA).

The missile hit a target after flying over waters in the East Sea for around 1,400 seconds, KCNA said, without disclosing other details such as how many missiles were fired.

The South Korean military said Wednesday it detected several cruise missile launches at around 9 a.m. into waters northeast of the eastern city of Wonsan.

It marked North Korea's fifth cruise missile launch this year. The provocation came two days before the 82nd birthday of late former leader Kim Jong-il, the father of the current leader Kim Jong-un.

The North Korea's leader ordered a stronger defence posture near the western maritime border, saying that South Korean warships have frequently violated it, KCNA said.

"If the enemy violates the maritime border that we've recognized, we will regard it as an infringement on our sovereignty and an act of a military provocation," Kim said.

North Korea has not recognized the Northern Limit Line, the de facto maritime border in the Yellow Sea, long demanding that the line be moved farther south as it was unilaterally drawn by the US-led UN Command after the 1950-53 Korean War.