Alarmed by North Korea's threat to launch ballistic missiles at Guam, the governors of four prefectures petitioned the central government Monday to strengthen efforts to protect residents from missile debris and other life-threatening contingencies.

The governors of Shimane, Hiroshima, Kochi and Ehime met Prime Minister Shinzo Abe and the vice ministers of the foreign and defense ministries to request "an utmost effort" to ensure their residents' safety.

Pyongyang's latest threat is "egregious" and "intolerable," Abe said at the start of his meeting with the four. "The government's biggest responsibility is to protect the lives of our citizens, and to this end, we will do whatever we can," Abe told them, emphasizing Tokyo will maintain a high level of cooperation with Washington and Seoul.