The US will deploy 14 additional ground-based defence missiles against the growing threat from North Korea, Chuck Hagel, the US defence secretary, has announced.

The interceptors will be based in Fort Greely, Alaska.

In addition, new radar capability will be installed in Japan to track any missiles fired by North Korea, Hagel said on Friday.

The US already has 30 interceptors in place in California and Alaska and the additional weaponry would be fielded by 2017, he said.

Al Jazeera's Rosiland Jordan reports from Washington DC.