North Korea's leader Kim Jong-Un has guided a military drill simulating an attack and seizure of a frontline South Korean island, Pyongyang's state media said Saturday.
The drill came as tensions grow ahead of an annual US-South Korea joint Key Resolve/Foal Eagle military exercise that is reportedly to start early next month.
Artillery units were among the troops taking part in the drill on the islets of Mu and Jangjae "in the biggest hotspot in the southernmost part of southwestern front", Pyongyang's Korean Central News Agency (KCNA) said.
The defence detachment on Mu Islet shelled South Korea's Yeonpyeong island in 2010 in an angry reaction to a firing drill conducted by the South near the disputed sea border in the Yellow Sea, killing four South Koreans.
Kim Jong-Un in 2012 visited Mu and Jangjae, honouring the troops on Mu Islet with the title of "Hero Defence Detachment". He made two more trips to the frontline islands in 2013 and threatened to "wipe out" Yeonpyeong Island and other South Korean islands near the border.
"Whenever the artillerymen hit targets, Kim Jong-Un expressed his great satisfaction, saying that they were very good at the concentration of fire and such shell-fire would remove the enemy island totally", KCNA said.
He called for the entire North Korean army to step up training to "bring the anti-US confrontation to the final conclusion by crushing the enemies promptly in case they pounce upon the DPRK (North Korea), it added.
Both sides complain of frequent maritime incursions by the other. The disputed sea border in the Yellow Sea saw deadly clashes in 1999, 2002 and 2009.
In October last year, naval patrol boats of the two rivals briefly exchanged warning fire near Yeonpyeong island.
The de-facto maritime boundary between the two Koreas -- the Northern Limit Line -- is not recognised by Pyongyang, which argues it was unilaterally drawn by US-led United Nations forces after the 1950-53 Korean War.
The war ended in an armistice instead of a peace treaty, leaving the two Koreas still technically at war.
North Korea launched winter drills in November last year and since then, Kim has inspected 10 different military units, according to South Korea's defence ministry.
He has been urging the military to complete war preparations this year, the defence ministry last week told the National Assembly's defence committee.