The US Department of Defence said it would deploy the ballistic Terminal High Altitude Area Defense System (THAAD) in the coming weeks.
Pyongyang has threatened to target South Korea and the US in recent weeks.
The North Korean warlike rhetoric follows new UN sanctions and joint military drills by the US and South Korea.
The Thaad system includes a truck-mounted launcher, interceptor missiles, and AN/TPY-2 tracking radar, together with an integrated fire control system.
The Pentagon said in a statement the missile system would be moved to Guam as a “precautionary move to strengthen our regional defence posture against the North Korean regional ballistic missile threat”.
“The United States remains vigilant in the face of North Korean provocations and stands ready to defend US territory, our allies, and our national interests,” the statement added.
In recent weeks, North Korea has mentioned military bases in the US territory of Guam and the US state of Hawaii as possible targets.
“Some of the actions they’ve taken over the last few weeks, present a real and clear danger,” said Defence Secretary Chuck Hagel, in his first major speech on Wednesday since taking up his post.
Chuck Hagel added that Pyongyang had also threatened the interests of South Korea and Japan.
PoDvkOr76tEThe US House Ethics Committee has voted to release its report on former Republican Representative…
ABC News has agreed to pay $15 million to President-elect Donald Trump to settle a…
South Korea’s parliament has voted to impeach President Yoon Suk Yeol over his failed attempt…
Israeli war planes have carried out more than 100 air strikes in Syria on December…
President-elect Donald Trump has threatened to impose 100% tariffs on the BRICS countries if they…
Syrian troops have withdrawn from the city of Aleppo following an offensive by rebels opposed…