BRUSSELS, Rabi'II 02, 1437, January 12, 2016, SPA -- NATO allies cannot agree to Russian demands to limit their missile defences because of the threat posed by North Korea, a senior U.S. State Department official said on Tuesday, according to Reuters. North Korea's claim last week to have tested a hydrogen bomb, which would represent an advance in its capability to strike Japan and the United States, has underscored Washington's determination to enhance the defences that Russia opposes. "We are not going to agree to limitations on our systems because we need to have the flexibility to deal with the dynamic and evolving threat," Frank Rose, deputy assistant secretary of state for arms control, told reporters at NATO in Brussels. "North Korea has large numbers of ballistic missiles and they test them often," Rose said, adding North Korea could already reach South Korea and most of Japan and potentially the United States. --SPA 22:15 LOCAL TIME 19:15 GMT www.spa.gov.sa/w