Japan's naval transport ship Kunisaki sailed for Okinawa carrying the ground-based Patriot Advanced Capability-3 missile interceptors to be placed at several sites on Okinawa, the Japanese news service Kyodo News reported.
North Korea, according to its official Korean Central News Agency, intends to launch its Unha-3 rocket between Dec. 10 and Dec. 22 from the Sohae Space Center in North Phyongan province to place an "Earth observation satellite" into orbit. The Communist country's attempt to launch a long-range rocket in April failed.
Kyodo reported the Kunisaki and another Japanese military transport ship, the Osumi, would arrive in Okinawa in a few days.
Separately Monday, South Korea's Yonhap News Agency quoted a Seoul government source as saying North Korea had installed the first stage of its three-stage, long-range rocket on its launch platform despite international warnings against the launch.
The source and South Korean intelligence officials told Yonhap it would take up to four days to set up all three stages.
"That means North Korea is starting its process of launching a long-range missile," the unnamed source said.
While the North has said its launch is meant to put a satellite in space, critics say it will actually be to test its intercontinental ballistic missiles capable of carrying nuclear warheads.
Yonhap, quoting a diplomatic source in Seoul, reported that prior to its public announcement Saturday North Korea had notified Japan and other countries within the projected path of its scheduled rocket firing.
China, North Korea's ally, expressed concern about the North's plans, saying it hoped relevant parties would act in a way more conducive to the stability of the Korean Peninsula, the official Xinhua News Agency reported.
Chinese Foreign Ministry spokesman Qin Gang said North Korea has a right to peaceful uses of outer space, but the right should be exercised within limitation of the U.N. Security Council resolutions.
In its announcement, carried by the KCNA, a spokesman for the North Korean space technology had said: "Scientists and technicians of [North Korea] analyzed the mistakes that were made during the previous April launch and deepened the work of improving the reliability and precision of the satellite and carrier rocket. The long-range rocket in April crashed into the sea after traveling a short distance, the report said.
Xinhua said the U.N. Security Council had condemned the April launch, demanding North Korea to fully comply with its resolutions and suspend all activities related to its ballistic missile program.
The U.S. State Department in a statement said the North Korean launch would be "a highly provocative act" for the peace and security in the region and that any launch using ballistic missile technology would be in direct violation of U.N. Security Council Resolutions 1718 and 1874.
"Devoting scarce resources to the development of nuclear weapons and long-range missiles will only further isolate and impoverish North Korea," the State Department said.
South Korea also said the launch would be "a severe provocation" and "a direct challenge to the international community as a whole."