South Korea's Defense Ministry has crossed out its definition of North Korea as an enemy in the 2018 defense white paper, released on Tuesday.

For the South Korean military, North Korea has long been an enemy whose nuclear weapons and missiles pose major threats to the security of the country.

However, the 2018 defense white paper describes "enemy" in a broader term that includes "any potential or transnational and nonmilitary threats," according to the Defense Ministry.

The toned down statement came in light of the fast-improving relationship between North Korea and South Korea after three summits between South Korean President Moon Jae-in and North Korean leader Kim Jong Un last year.

The two leaders agreed to take steps to ease military tension between the two countries, such as closing front-line guard posts on the border.

"The tensions on the Korean Peninsula surged after North Korea conducted its 6th nuclear test in 2017, but a new security environment is shaping with the (South Korean) government's effort for denuclearization on the Korean Peninsula and settlement for peace," the 2018 defense white paper said.

The previous 2016 white paper states that North Korea's nuclear weapons, cyber-attacks and terrorism pose major threats to South Korea's security and the regime remains an "enemy insofar as they are the agents carrying out these threats."

South Korea publishes its defense white paper every other year.

The Defense Ministry has stated North Korea as an enemy in white papers since 2010 when North Korea attacked the South's westernmost border island of Yeonpyeong. North Korea fired artillery shells and rockets to the island, killing four and injuring 19.

The 2018 defense white paper features updated military information on North Korea.

According to the paper, North Korea has recently created a special forces team in charge of assassination missions.

The South Korean Defense Ministry also estimates that North Korea has some 50 kilograms of plutonium enough to create nuclear weapons through the reprocessing of spent fuel rods from its nuclear plants.

It also has a considerable amount of enriched uranium and is capable of reducing the size of nuclear weapons.

Bloomberg reported Monday that North Korea continues to develop its nuclear weapons and missiles as opposed to the pledge by North Korean leader Kim Jong Un to denuclearize, based on its analysis on satellite imageries and intelligence information.

Last week, the United States Forces Japan released a video, in which it defines North Korea as one of the "three declared nuclear states" in the Northeast Asian region, along with Russia and China. The video describes North Korea a state with 15 nuclear weapons.