North Korea has deployed 250 ballistic missile launchers to its southern border, with leader Kim Jong Un describing the weapons as a 'powerful treasured sword' to defend its sovereignty, state media said Monday.

The olive green mobile launchers were displayed during a special 'transferring' ceremony in the capital Pyongyang on Sunday, the official Korean Central News Agency reported.

The missile launchers were an 'up-to-date tactical attack weapon', Kim was quoted as saying in a speech.