Photos released by North Korean official news outlet Rodong Sinmun on 9 March showed the country's leader, Kim Jong-un, meeting the country's nuclear technicians at what could be a
KN-08 (Hwasong-13) intercontinental ballistic missile production facility near Jonchon in the country's northern Chaggang province.
The accompanying article said Kim was congratulating his nuclear weapon scientists for having developed a miniaturised nuclear warhead: a claim being met with scepticism by various Western analysts.
The photos and article came two days after Pyongyang threatened its South Korean neighbours with a pre-emptive nuclear strike for the 7 March initiation of joint exercises
'Foal Eagle' and 'Key Resolve': the largest set of manoeuvres ever conducted with US forces in the region, in which around 17,000 US troops are exercising alongside some 300,000 South Korean military personnel.
In the week prior to the beginning of the exercises, Pyongyang's KCNA state news agency quoted Kim as saying that North Korea's
"nuclear warheads need to be ready for use at any time".