The United States has concerns about a possible North Korean missile launch towards Hawaii and has taken steps to ensure the protection of US territory, Defense Secretary Robert Gates said on Thursday, according to AFP.
"We do have some concerns if they were to launch a missile ... in the direction of Hawaii," Gates told a news conference.
The defense secretary said he had approved the deployment of THAAD missile defense weaponry to the US state and radar "to provide support" in case of a possible North Korean missile attack.
"I would just say I think we are in a good position should it become necessary to protect American territory," he added.
US and South Korean officials have said North Korea might be readying another ballistic missile test after three previous launches in 1998, 2006 and this year.
Pyongyang said its latest April 5 launch put a satellite into orbit, while the United States and its allies labelled it a disguised test of a Taepodong-2 missile theoretically capable of reaching Alaska.
Japan's defense ministry believes that North Korea might now be planning to launch a two-stage or three-stage Taepodong-2 missile towards either Japan's Okinawa island, Guam or Hawaii, the Japanese daily Yomiuri Shimbun reported on Thursday.
But the ministry said launches toward Okinawa or Guam were "extremely unlikely" because the first-stage booster could drop into waters off China, agitating Beijing, or hit western Japanese territory, the report said.
If the missile were fired in the direction of Hawaii, the booster could drop in the Sea of Japan (East Sea) well before the missile's remaining part flies over northern Japan and towards North America.
Tensions on the Korean peninsula have mounted after Pyongyang carried out its second nuclear test last month.
On Saturday, the North vowed to build more atomic bombs and start enriching uranium for a new nuclear weapons program, in response to new UN sanctions.