North Korean missile tests didn't violate Kim Jong Un's pledge to Trump: John Bolton

"The firing of these missiles don't violate the pledge that Kim Jong Un made to the President about intercontinental-range ballistic missiles," Mr Bolton said in an interview on Fox Business Network.

"But you have to ask when the real diplomacy is going to begin, when the working-level discussions on denuclearisation will begin, as Kim Jong Un again said on June 30 he was prepared to do. We're still waiting to hear from North Korea," the national security adviser said.

Mr Bolton also said that the United States will renew sanctions waivers for Iran nuclear programmes that allow Russia, China and European nations to continue civilian nuclear cooperation with Teheran. 

“I think the idea here is we are watching those nuclear activities very, very closely,” Mr Bolton said.

“So this is a short 90-day extension,” he said.