Japan on Friday, March 23, readied its missile defense systems to shoot down a North Korean rocket if it threatens the country, as the UN chief warned that next month's launch could jeopardize food aid, according to AFP.

"I have ordered officials to prepare to deploy the PAC-3 and Aegis warships," Japan's Defense Minister Naoki Tanaka told reporters, referring to surface-to-air missiles and destroyers carrying missiles.

The nuclear-armed North has announced it will launch a rocket in mid-April to put a satellite into orbit, a move that the United States, South Korea and other nations see as a pretext for a long-range missile test banned by the UN.

The move by North Korea's new leadership has set off alarm bells across the region. The Philippines is calling for help from the United States to monitor the rocket, part of which is expected to land off the archipelago.

The preparations by Japan, regularly the target of North Korean barbs, come as world leaders including US President Barack Obama prepare to meet in Seoul for a summit officially focused on nuclear terrorism.