North Korea has recently changed the name of its military development agency, which had been deceitfully called a science lab, in a way that clarifies its mission of weaponry research, a source said Monday.

Early last year, North Korea returned the Second Academy of Natural Sciences to its old name of the Academy of the National Defense Science, according to the source familiar with North Korean affairs.

The ANDS was set up in 1964 as an institute dealing with defense development. It is known to have been renamed the Second Academy of Natural Science after the 1970s in a bid to disguise its work on weapons development.

"North Korea internally calls the agency the ANDS, but when it needed to conceal the organization's identity, it used the name of the Second Academy of Natural Sciences," said Lee Choon-geun, a senior research fellow at the Science and Technology Policy Institute.

North Korean leader Kim Jong-un watched a ground jet test of a new type of high-thrust rocket engine newly developed by the ANDS, according to the Korean Central News Agency.

The state media's report on the agency indicates North Korea would not hide its intention to develop advanced weapons with the goal of developing a nuclear-tipped missile.

The North's leader said in his New Year's message that the country has entered the final stage of preparing to launch an intercontinental ballistic missile.

South Korea's defense ministry said that North Korea's latest engine test was a "meaningful" advance in its weapons of mass destruction development program.

The Second Academy of Natural Sciences was blacklisted by the UN Security Council in 2013 as an agency engaged in or providing support for North Korea's nuclear and ballistic missile programs through various means, including illicit ones, according to the UN website.

In November 2016, Jang Chang-ha, the head of the agency, became one of 11 individuals who were newly added to the UNSC's sanctions list.(Yonhap)