A senior U.S. defense official said on Tuesday that any nuclear attack by North Korea will be met with nuclear retaliation by the United States.

John Hill, the deputy assistant secretary of defense for space and missile defense, made the remarks during a hearing of a subcommittee of the House Armed Services Committee of the U.S. Congress.

The assertion by Hill came in response to a lawmaker’s question about the point at which the U.S. would contain the North's nuclear threat not just with missile defense but with nuclear weapons.

Mentioning the U.S. Missile Defense Review(MDR) released last October, the official said that U.S. capabilities to impose costs on North Korea include a response with nuclear weapons, which has always been part of the deterrence posture on North Korea.

The MDR stated that the U.S. will counter North Korean missile threats through a “comprehensive missile defeat approach” complemented by direct cost imposition through nuclear and non-nuclear means.

Hill said that nuclear retaliation and strategic deterrence would also play a role in responding to an attack by the North with nuclear weapons.