Kerry says US will defend South Korea with 'extended deterrence'

US Secretary of State John Kerry says the US will 'defend South Korea through a robust, combined defence posture and through extended deterrence, including the US nuclear umbrella conventional strike and missile defence capabilities.'

WASHINGTON, DC (Reuters) - The United States vowed on Wednesday (Oct 19) to do "whatever is necessary" to defend itself, South Korea and other allies against the "grave" threat posed by North Korea, which has conducted two nuclear tests and a series of missile launches this year.

US Secretary of State John Kerry held a news conference with South Korean Foreign Minister Yun Byung Se to discuss their response to the threat posed by North Korea in wake of their nuclear test last month.

"Our two governments have joined countries across the globe in condemning North Korea's latest nuclear test and its repeated ballistic missile tests," said Mr Kerry.

The Secretary promised the United States would "defend South Korea through a robust, combined defense posture and through extended deterrence including the US nuclear umbrella conventional strike and missile defense capabilities".

US Defense Secretary Ash Carter said at the start of talks in Washington between the foreign and defense ministers of the United States and South Korea that the US commitment to provide "extended deterrence, guaranteed by the full spectrum of US defense capabilities" was "unwavering".

The term "extended deterrence" refers to the US nuclear umbrella that protects non-nuclear allies South Korea and Japan in East Asia.

South Korean Foreign Minister Yun Byung Se said North Korea was nearing the "final stage of nuclear weaponisation" and called for "an updated US-Korean comprehensive response strategy." He said the allies should mobilise "all tools in the toolkit" to defend themselves.