US military forces have reportedly taken part in a series of drills to practice taking out North Korean leader Kim Jong-Un in the event of an attack on the South by Pyongyang.

The nuclear-powered aircraft carrier USS Ronald Reagan, which is owned by the US and carries three separate air-to-surface missile systems, joined South Korean forces for six days of exercises in the Sea of Japan.

A defence ministry official confirmed one section of the drills - named ‘Invincible Spirit’ - involved plans to remove the North Korean leadership in case aggression between the two countries escalates, according to local news agency Yonhap.

“The Invincible Spirit exercise is aimed at showing the allied forces’ strong commitment to counter relentless provocations by the North and improve their maritime interoperability,” the South Korean navy said in a statement.

US navy operatives conducted anti-submarine, anti-aircraft and precision-guided striking operations off the coast of the Korean Peninsula, according to Japan Times.

South Korea meanwhile mobilised 40 missile warships with special forces to practice intercepting North Korean attacks and target nuclear weapons sites.

The two countries last conducted joint naval drills in July 2010, after 46 sailors died in the sinking of a South Korean ship by the North.

Last month, South Korea’s defence minister Han Min-Koo announced the country was assembling a military plan labelled ‘Korea Massive Punishment and Retaliation’ (KMPR) to take out Kim Jong-Un if a nuclear strike was imminent.

Inside the daily life in North Korea Show all 19 1 /19 Inside the daily life in North Korea Inside the daily life in North Korea People reading a newspaper at the metro station Inside the daily life in North Korea Thoughts of the leaders on the tram. They have about a dozen of these on every tram, all with different thoughts Inside the daily life in North Korea Young people training for a big upcoming festival Inside the daily life in North Korea People at the Pyongyang's annual marathon Inside the daily life in North Korea Many stars on one of the trolleys in Pyongyang Inside the daily life in North Korea An intimidating poster in a primary school in North Korea. Inside the daily life in North Korea Solar panels installed on a street lamp. Inside the daily life in North Korea A poster on the window next to one of the venues we visited in Pyongyang Inside the daily life in North Korea Kids playing football next to the Arch of Triumph. After a while tourists were allowed to join, so some of us did Inside the daily life in North Korea Class in an educational center in Pyongyang (where people over 17 years old can attend any classes they choose after school, for free) Inside the daily life in North Korea People waving at me during the Pyongyang marathon Inside the daily life in North Korea People having a great time dancing at a public park Inside the daily life in North Korea A metro driver in a metro station in Pyongyang Inside the daily life in North Korea Fireworks to mark the birthday of the Eternal President Kim Il Sung on our last night in Pyongyang Inside the daily life in North Korea My wonderful tour guide at a public park Inside the daily life in North Korea One of the parks in Pyongyang Inside the daily life in North Korea A person rowing some boats for the day at a river in Pyongyang Inside the daily life in North Korea The National War Museum Inside the daily life in North Korea Public park in Pyongyang

“If it becomes clear the enemy intends to use nuclear-tipped missiles, in order to suppress its aims, the concept of the KMPR squad is to retaliate against key areas that include the North Korean leadership,”, Mr Han told the National Assembly in Seoul.

North Korea’s ability to use nuclear weapons is increasing “with each passing month”, former US State Department negotiator Robert Gallucci recently warned.