US Defence Secretary Chuck Hagel has announced plans to bolster US missile defences in response to a growing nuclear threat from North Korea.
14 interceptors will be added to a missile defence site in Alaska by 2017 and a radar tracking station will be deployed in Japan.
"The reason that we're doing what we're doing ... is to not take any chances, is to stay ahead of the threat," Hagel said.
More top news
Too many patients who undergo emergency bowel surgery are dying because of inconsistent care practices, health experts have warned.
A report by a think-tank that claims more than half of households take more in benefits than pay in tax has been condemned as 'spin'.
The Education Secretary has set her sights on 'coasting' schools that have "fallen under the radar" with plans to force improvements.