North Korea: We will accelerate our nuclear programmes

North Korea says it has nothing to fear from any US move to extend sanctions, and will "accelerate" its nuclear programmes, according to a report.

The acceleration includes developing a "pre-emptive first strike capability", and an inter-continental ballistic missile (ICBM), according to Choe Myong Nam, deputy ambassador at the DPRK (North Korean) mission to the United Nations in Geneva.

There were reports on Monday that the Trump administration is considering broadening sanctions as part of a review of measures aimed at countering North Korea's nuclear and missile threat.

"I think this is stemming from the visit by the Secretary of State (Rex Tillerson) to Japan, South Korea and China...We of course are not afraid of any act like that," Choe told Reuters.

"Even prohibition of the international transactions system, the global financial system, this kind of thing is part of their system that will not frighten us or make any difference.

"In the light of such huge military forces involved in the joint military exercises, we have no other choice but to continue with our full acceleration of the nuclear programs and missile programs. It is because of these hostile activities on the part of the United States and South Korea."