North Korea must stop blocking talks with the US before it is too late, said US Special Envoy for North Korea Stephen E. Biegun, AFP reported. 

"If we are to succeed, North Korea must set aside its search for obstacles to negotiations and instead seek the opportunities for engagement while that opportunity lasts," Stephen Biegun said Friday in a speech at the University of Michigan.

He once again criticized the idea of ​​a phased approach, advocated by some experts, to ease sanctions in return for the North to take steps towards denuclearization.