TOKYO - Japan on Friday ordered it’s military to shoot down a North Korean rocket if it threatens the nation’s territory as Washington put anti-missile destroyers into position, ramping up pressure on Pyongyang. The moves came as a US think tank said recent heavy snow could hamper the hermit nation’s launch effort. Tokyo has readied surface-to-air missiles in and around the capital, as well as in Okinawa, and has deployed Aegis warships in neighbouring waters. Prime Minister Yoshihiko Noda, who is facing an uphill election battle this month, visited the defence ministry in Tokyo where Patriot missile batteries stood ready.