North Korea to deliver 'ruthless blow' if provoked by US: Envoy

North Korea is ready to deliver the "most ruthless blow" if provoked by the United States, its ambassador to Moscow said on Thursday.

"Our army has already said that if there will be even the smallest provocation from the United States during exercises, we are ready to deliver the most ruthless blow," Interfax news agency quoted ambassador Kim Hyong Jun as saying, adding that his country had the "readiness and ability to counter any challenge from the US.