South Korean and U.S. military leaders have signed a new joint operational plan which would allow U.S. troops to take part in action against North Korea, the country's defence ministry said.

The military agreement was signed between South Korea's Joint Chiefs of Staff Chairman Jung Seung-jo and the commander of the U.S. Forces in South Korea, James Thurman, on Friday (March 22nd).

The Combined Counter-Provocation Plan went into effect immediately after the signing amid rising tension on the peninsula.

In the past, South Korean troops were unilaterally in charge of any military action against North Korea and the U.S. troops would engage only if a full-scale war broke out, according to the defence ministry.

After North Korea's shelling of a South Korean island which killed two civilians in 2010, and the sinking of a South Korean naval vessel the same year widely blamed on the North, Seoul has pledged to defend itself by retaliating against the source of any attack.

South Korea's 640,000 South Korean troops are backed up by 26,000 U.S. personnel stationed in the country, which has been divided into North and South more than 60 years since the 1950-53 Korean War ended in a truce.

Presented by Adam Justice