South Korea and the U.S. will stage a massive exercise next month to train their marines on landing on the North Korean coast and moving to inland targets.

According to defense officials in Seoul, this year's annual "Ssangyong," or "Double Dragon," exercise will focus on the later phase of operations to advance deeper into key facilities in inland areas.

The joint annual exercise between the marine forces of South Korea and the U.S. was first launched in 2012. This year’s drill, which will begin on March 8, is expected to mobilize around three-thousand South Korean marines and seven-thousand American marines.

The marine exercise will be held on the largest-ever scale not only in terms of the size of personnel participation but also in the number and kinds of strategic assets to be mobilized.

Seoul’s defense officials explained that the annual drill will reinforce inland operations this year, marking a shift from its usual focus on amphibious vehicle landings.

The exercise will require troops to move longer distances and train for an extended period compared to previous training exercises.

The intensified drill is part of the newly formulated Operations Plan 5015, which calls on South Korean and U.S. forces to conduct preemptive attacks if North Korea is seen preparing for provocation.

Military experts said that the up scaling and change of focus indicates that the South Korea-U.S. allied forces are determined to respond differently to North Korean provocations from now on, instead of the mere showing of force in the past.