NORTH Korea has hit the "provocation pause" button on its aggressive nuclear rhetoric after pressure from China, as Kim Jong-Un literally watches grass grow.

CBS News reports two Musudan medium-range missiles have been packed up and moved from their launch sites on the coast of the Sea of Japan.

US intelligence reportedly warns that the missiles are mobile, and the move does not necessarily mean they can't be set to fire with little or no warning.

The move coincides with the ending of joing US-South Korean military exercises.

Pentagon spokesman George Little, who would not confirm that the missiles have been moved, said "what we have seen recently is a provocation pause."

Mr Little said pressure from North Korea’s main ally China, other regional powers and "a range of factors" are behind North Korea’s decision to "rachet back" from recent military tensions.

China "made some helpful statements" to help put a lid on North Korea’s bluster against the US, Mr Little said.

Meanwhile, it seems North Korean leader Kim Jong-Un has taken some time out from stoking nuclear fears to inspect grass growing. A series of photos released by North Korea show the young dictator inspecting what is said to be the new Turf Institute of Bioengineering in a Pygongyang suburb.

Kim is seen examining the bright green grass as his officials take notes, and even shows them how to best hold some gardening equipment in the carefully staged photos

The new, strategic silence from North Korea comes after escalating tensions that raised fear of a nuclear attack.

In February, North Korea conducted an underground nuclear test that was condemned by the international community. In March, US-South Korea military exercises on the Korean peninsula sent Pyongyang into a frenzy, sparking increasingly aggressive rhetoric from the rogue state, led by young leader Kim Jong-Un.

However, Mr Little downplayed the incidents as part of North Korea’s history of military threats to force aid and concessions from the international community.

This week, North Korea denied it was using jailed US citizen and tour guide operator Kenneth Bae as a “bargaining chip” after sentencing him to 15 years hard labour for alleged “hostile acts” it says were aimed at toppling the regime. Mr Bae is believed to have taken photographs of emaciated children in North Korea as part of efforts to raise outside aid.

