North Korea leader
North Korean leader Kim Jong Un supervised a ballistic rocket-launching drill of Hwasong artillery units of the Strategic Force of the KPA on the spot in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang, March 7, 2017. Reuters

As tensions escalate in East Asia, North Korea may be closing in to conducting its sixth underground nuclear test, a report citing intelligence gathered by the United States said Friday.

Two U.S. officials, speaking to CNN, said there existed satellite imagery of the Punggye-ri test site, which showed significant changes on the site. The images regularly show military personnel, vehicles and equipment along with two tunnel entrances that could have been dug for use during the underground test.

Read: Kim Jong Un's Regime Issues Threat To US Over Possible Preemptive Strike

The latest images, however, showed a complete stoppage of such activity, as was the case before Pyongyang’s previous nuclear tests. According to the officials, this shows that the final preparations had concluded. A similar statement was issued by U.S.’ ally South Korea.

“It is assessed that North Korea is ready to carry out a nuclear test anytime if its leadership decides to do so,” Ministry of Unification spokesman Lee Duk-haeng said in a press briefing. “South Korean and U.S. intelligence authorities evaluate that North Korea is ready to carry out a nuclear test anytime on the leadership's decision”

Pyongyang has been hinting at further tests and a North Korean envoy said Tuesday that their Supreme Commander Kim Jong Un will launch an intercontinental ballistic missile “at any time and at any place” that he pleased.

The U.S. and South Korea have been attempting to deter the North Korean nuclear threat and a powerful long-range bomber was flown over the Korean peninsula Wednesday. U.S. Secretary of State Rex Tillerson, during a trip to Seoul last week, said preemptive strikes “were on the table” if the U.S. and its allies were threatened with North Korea’s nuclear program.

In response, Pyongyang’s official mouthpiece KCNA published an article titled “U.S. should not run wild, pondering over the catastrophic consequences to be entailed by its attempt at a preemptive strike.”