White House National Security Communications Advisor John Kirby said the US is closely monitoring this Russian activity and will continue to take it seriously amid reports of Moscow reportedly developing a space-based nuclear weapon designed to disable or destroy satellites. "While I am limited by how much I can share about the specific nature of the threat, I can confirm that it is related to an anti-satellite capability that Russia is developing. I want to be clear about a couple of things right off the bat", John Kirby said.