By Phil Stewart and David Alexander
WASHINGTON (Reuters) - The United States said on Wednesday it will soon send a missile defense system to Guam to defend it from North Korea, as the U.S. military adjusts to what Defense Secretary Chuck Hagel described as a "real and clear danger" from Pyongyang.
North Korea has threatened a nuclear strike on the United States and missile attacks on its Pacific bases, including in Guam, a U.S. territory in the Pacific, since new U.N. sanctions were imposed over the country's third nuclear weapons test in February.
One of the most isolated and unpredictable states in the world, North Korea also said on Tuesday it would revive a mothballed nuclear reactor able to produce bomb-grade plutonium.
"Some of the actions they've taken over the last few weeks, present a real and clear danger," Hagel told an audience at the National Defense University in Washington.
Hagel said he had to take the threats seriously, language he has used in recent weeks as the United States revamped its missile defense plans and positioned two guided-missile destroyers in the western Pacific to bolster missile defense.
The United States has also flexed its muscle during military drills with South Korea last week, flying two bat-winged stealth bombers on a first-of-its-kind practice bombing run over South Korea.
In the latest move, the Pentagon said on Wednesday it was deploying a Terminal High Altitude Area Defense system to Guam in the coming weeks. The THAAD system includes a truck-mounted launcher, interceptor missiles, an AN/TPY-2 tracking radar and an integrated fire control system.
"The United States remains vigilant in the face of North Korean provocations and stands ready to defend U.S. territory, our allies, and our national interests," a Pentagon spokeswoman said.
Hagel called America's responses so far "measured, responsible, serious" and also said the United States was working with allies to lower tensions.
"We are doing everything we can, working with the Chinese, others to defuse that situation on the peninsula," he said.A North Korean nuclear plant is seen before demolishing a cooling tower (R) in Yongbyon, in this photo taken June 27, 2008 and released by Kyodo. North Korea is to restart the mothballed Yongbyon ... more? A North Korean nuclear plant is seen before demolishing a cooling tower (R) in Yongbyon, in this photo taken June 27, 2008 and released by Kyodo. North Korea is to restart the mothballed Yongbyon nuclear reactor that has been closed since 2007 in a move that could produce more plutonium for nuclear weapons as well as for domestic electricity production, its KCNA news agency said on April 2, 2013. As well as restarting the 5MW reactor at Yongbyon, the North's only known source of plutonium for its nuclear weapons programme, KCNA said a uranium enrichment plant would also be put back into operation, a move that could give it a second path to the bomb. Picture taken June 27, 2008. Mandatory Credit. REUTERS/Kyodo (NORTH KOREA - Tags: ENERGY POLITICS TPX IMAGES OF THE DAY) FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. MANDATORY CREDIT. JAPAN OUT. NO COMMERCIAL OR EDITORIAL SALES IN JAPAN. ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS. YES less? ?
In Beijing, China's deputy foreign minister met ambassadors from the United States and both Koreas to express "serious concern" about the Korean peninsula, China's Foreign Ministry said. It was a sign that China, the North's major benefactor, was increasingly worried about events spinning out of control.
Despite the rhetoric, however, Pyongyang has not taken any military action and has shown no sign of preparing its 1.2 million strong armed forces for war, the White House said on Monday.
The rising tensions did not appear to jolt markets, long accustomed to cycles of rising tensions on the peninsula.
"I would say that people are taking it a lot more seriously than they used to," said Steve Van Order, a fixed income strategist at Calvert Investments in Maryland.
(Editing by Sandra Maler and Mohammad Zargham)