* Cyber warfare new weapon in North Korea's arsenal
* April 'satellite' launch aimed at improving rocketry (Adds missile launch preparations detected in paragraphs 2, 12-14)
By Paul Eckert
WASHINGTON, March 28 (Reuters) - North Korea has added sophisticated cyber attack capabilities to its arsenal of threatening weapons and this year is rife with opportunities for military provocations from Pyongyang, beginning with a controversial rocket launch next month, senior U.S. defense officials said on Wednesday.
In a sign North Korea is moving forward with its announced plan to launch a rocket in mid-April, a U.S. official confirmed the United States had detected activity that looked like launch preparations at a facility near the country's northwestern border with China.
The U.S. military officials told the House of Representatives Armed Services Committee that North Korea's large conventional military, nuclear weapons programs, ballistic missiles and newer capabilities in cyber warfare all threatened the United States and its allies in the Asia-Pacific region.
Army General James Thurman, the commander of U.S. Forces Korea, told the panel that a skilled team of hackers was the newest addition to North Korea's capabilities that also include chemical and biological weapons.
"Such attacks are ideal for North Korea, providing the regime a means to attack (South Korean) and U.S. interests without attribution, and have been increasingly employed against a variety of targets including military, governmental, educational and commercial institutions," he said in prepared comments.
Thurman, who leads the 28,000 U.S. troops in South Korea, told the panel that the power transfer following the death in December of leader Kim Jong-il "appears to be proceeding without discernible internal challenges and with significant Chinese political and economic support."
Kim's untested son, Kim Jong-un, estimated to be 28 years old, has eased into power surrounded by allies of his father with so far "no indications the regime will depart significantly from Kim Jong-il's policies," said Thurman.
Peter Lavoy, acting assistant secretary of defense for Asia and Pacific Security Affairs, told the panel the potential for provocations from North Korea in 2012 was a "major concern" of the Pentagon.
MISSILE COURSE A CONCERN
From the U.S. perspective, the first provocation will be a North Korean ballistic missile launch slated for between April 12 and 16. But South Korean elections in April and December might also tempt Pyongyang to take actions to influence Seoul's domestic politics, he said.
Pyongyang says the rocket to be launched to mark the 100th birthday of deceased state founder Kim Il-sung will carry a weather satellite into orbit. But most outsiders say it is a disguised test of a long-range missile that violates key U.N. Security Council resolutions that ban any such launches.
"This planned launch is highly provocative because it manifests North Korea's desire to test and expand its long-range missile capability," said Lavoy. He said the announcement of the launch also broke a missile moratorium North Korea agreed to on Feb. 29 with Washington in exchange for food aid.
The website GlobalSecurity.org published satellite imagery last week of a launch pad and tower without a rocket at the Tongchang-dong launch site. A U.S. official indicated there were signs the North Koreans were getting the site ready.
"The U.S. has seen indications that the North Koreans are preparing to launch a long-range rocket," said the official.
Pentagon spokeswoman Leslie Hull-Ryde said the United States and South Korea were monitoring North Korea, but declined to comment on specific intelligence on the launch.
Many of North Korea's neighbors are concerned about next month's launch of a rocket, which North Korea has said would travel southward toward the Philippines or Indonesia, Lavoy told U.S. lawmakers.
"I don't know if we have any confidence on the stability of the missile or what the impact will be," he said.
The planned launch has put on hold diplomatic efforts to coax North Korea back into talks over its nuclear weapons programs that have been frozen for three years.
Pyongyang often shifts tactics between diplomacy and confrontation, said Thurman.
"History tells us that Pyongyang will shift from diplomatic to provocative behavior when conventional diplomacy has run its course and the North Korean leadership perceives coercive diplomacy offers a better chance to realize its objectives," he said. (Additional reporting by David Alexander and Mark Hosenball; editing by Lisa Shumaker and Mohammad Zargham)