Japan may shift Patriot missile batteries to its northern coast to intercept debris that might be created if North Korea's rocket launch fails, the defense minister said Thursday as the prime minister warned of more sanctions against Pyongyang.

Defense Minister Yasukazu Hamada said some of the six PAC-3 missile batteries now protecting Tokyo may be shifted to intercept fragments that might fall on Japanese soil if North Korea's rocket malfunctions in midflight. The missile is expected to be launched between April 4 and 8.

"We are considering various measures, including that," Hamada told reporters.