The US intelligence community and defence officials are anticipating that North Korea will soon carry out a new round of testing of its missile and nuclear programme, a media report said on Friday.
The officials are closely monitoring the regime's programmes and there are growing intelligence indicators of fresh and concerning activity inside North Korea, CNN said in the report.
The major source of that intelligence for the US is spy satellites that survey the regime from overhead, so there is little ability to fully understand what leader Kim Jong-un may decide to do, according to the officials.
The satellites have watched a test site for several weeks and seen fresh signs of digging and activity at tunnel entrances.
The commercial website 38 North recently posted satellite imagery showing continuing activity at the Punggye-ri nuclear test site indicating the area was ready for an underground test as soon as one is ordered by leader Kim Jong-un.
However, North Korea is taking fresh steps to disguise its activities, knowing overhead satellites are watching.
The latest indicators, the US officials told CNN, is that North Korea has moved some launch equipment that is associated with an intercontinental ballistic missile launch, believing that Washington cannot track them there.
The equipment has been observed near parade grounds, but the concern is it could quickly become part of an actual launch.