'We have to provide all options' on North Korea: NSA HR McMaster

White House National Security Advisor HR McMaster has said that North Korea possessing nuclear weapons capable of reaching the United States would be "intolerable" and could lead to a US military response.

McMaster, in an interview to MSNBC, said, "If they had nuclear weapons that can threaten the United States, it's intolerable from the President's perspective. Of course, we have to provide all options to do that, and that includes a military option."

When asked how concerned the American people should be about the possibility of a war with North Korea to end its nuclear threat, McMaster said Pyongyang poses an extreme danger.

"I think it's impossible to overstate the danger associated with a rogue, brutal regime, I mean, who murdered his own brother with nerve agent in an airport. I mean, think about what he's done, in terms of his own brutal repression of not only members of his regime but his own family," he said.

He added that he expects U.S. allies to recognise North Korea is a global threat that "requires global action."

On the topic of sanctions against Russia, McMaster said that country "must play a much more responsible role in the world -- if it's going to be a full-fledged, welcomed member of the international community."

"What the President has asked us to do is, and -- and the secretary of state is doing -- is to counter Russia's destabilizing behavior where it affects our interests, to take actions to deter any -- any-- escalation of conflicts or anything that could lead to a confrontation," McMaster said.

He added that Russia is undertaking a "sophisticated campaign of subversion and disinformation and propaganda," including its role tampering in the U.S. election, while also saying that Russia's destabilising activities in the United States and Europe and alliances with Syria and Iran do not mean Washington should stop trying to have a relationship with Moscow.