North Korea has long-range nuclear warheads which can reach Britain, continental Europe and the United States, a South Korean government official reportedly said Saturday. The statement came amid reports that the military of the Kim Jong Un-ruled country is now capable of attaching nuclear warheads to missiles which can travel a few thousand miles.

Lee Sang-haw, director general of North Korean nuclear affairs bureau in South Korea, told the Daily Star Online in Seoul that Kim's nuclear arsenal is more dangerous than previously thought, and that “Europe is also within range” along with other countries of the NATO alliance.

According to reports, North Korea's KN-08 missile — which is under development — will have a range of more than 7,500 miles.

“I am not able to share everything I know because much of the intelligence is classified and I don’t want to go into precise details," a senior South Korean ministry source reportedly said. “There are different assessments of North Korea’s ballistic missile capabilities, but what is for sure is as they repeat tests, they learn something important.”

Meanwhile, Yonhap reported Sunday, citing a local state-run think tank, that North Korea's ability to engage in special operational warfare has improved over the years. Pyongyang has continuously built up its nuclear and ballistic missile programs over the years.

"Every intelligence points toward a buildup of conventional arms," a source Korea Institute for Defense Analyses (KIDA), who declined to be identified, said.

As a case in point, officials gave the example of the North creating a battalion-size unit specially tasked with attacking the Blue House — the office and official residence of South Korea's president — and assassinating key figures in Seoul's government. Kim reportedly visited this battalion Nov. 4 and the troops were assigned to participate in a mock attack on the Blue House early last week.

North Korea faced criticism from the West and strong U.N. sanctions were imposed on it following its nuclear weapons tests and other ballistic missile launches.