North Korea has reshuffled its top military leadership, indicating the intractable country is likely to step up its saber-rattling and Cold War-style brinkmanship and lowering hopes of a peaceful resolution to the nuclear standoff, officials and analysts in South Korea say.

The military shakeup, which comes amid mounting signs of an imminent missile launch, is also aimed at tightening state control over the famine-hit population to prepare for another dynastic power transfer, they say.

Vice Marshal Kim Yong Chun, 73, has been named minister of the People's Armed Forces, or defense minister, replacing Kim Il Chol, who had been in the post since 2000, according to the North's official Korean Central News Agency.

Gen. Ri Yong Ho has been appointed chief of the army's General Staff, equivalent to the U.S. chairman of the Joint Chiefs of Staff, replacing Kim Kyok Sik, who had served in the post for the past two years.

Both the top military leaders are believed to be hawkish and among the closest aides to North Korean leader Kim Jong Il, who rules the country as the top military commander.

Kim Yong Chun, who led the army's General Staff for nearly a decade until 2007, has been a key player in the country's nuclear weapons and missile development, according to military sources in South Korea.

During Kim's term as chief of the General Staff, the North conducted nuclear and ballistic missile tests in 2006, which put the Asia-Pacific region on alert. The North's military under his rule also violated the inter-Korean maritime border and exchanged naval gunfire with the South in 1999 and 2002, which left dozens dead or wounded on both sides.

"Kim seems behind the North's provocative actions in the past decades," the military source said, describing the new defense chief as "hawkish." Kim served since April 2007 as vice chairman of the country's all-powerful National Defense Commission led by Kim Jong Il.

The new defense minister has also played a role in promoting the personality cult of Kim Jong Il and his royal family. He has indicated he will launch a loyalty campaign for Kim's potential successor, most likely to be one of his three sons. Kim, who turns 67 next week, is thought to have suffered a stroke last August, which could force him to speed up preparations for a father-to-son power transfer.

Little is known about Ri, except that he once served as chief of the Pyongyang Defense Command. Defectors from the North say Ri is in his early 60s.

The two new military leaders accompanied Kim Jong Il on a visit to an artillery unit, according to the North's news report on Thursday. The unit showed "the resolute determination of the servicemen to crush the aggressors at a single blow ... and their merciless striking capability," the report said.

Analysts in Seoul said the military shakeup is aimed at tightening Kim Jong Il's grip on power by installing his close confidants in top military posts. The North's 1.2 million-strong military, the world's fifth largest, is the backbone of his iron-fisted rule.

"With the reshuffle, Kim wants to run the military and the country more stably," said Kim Yong-hyun, who teaches North Korean affairs at Dongguk University in Seoul, noting there could be more reshuffles of key posts in the near future.

"The deployment of the hawkish figures to the top military posts is also designed to put more pressure on the United States and South Korea by demonstrating that it is ready to step up its saber-rattling," he said.

Kim and other analysts said they see a high possibility that the North would actually test-fire a ballistic missile despite global appeals and warnings. The North's future action largely depends on the outcome of U.S. Secretary of State Hillary Clinton's Asian tour, which will be focused on North Korea, they said.

North Korea appears to be gearing up to launch a long-range missile designed to carry a nuclear warhead that can hit U.S. territory. The missile, named Taepodong-2, already has reached the Musudan-ri launch site on its east coast.

A vehicle carrying radar equipment also was seen moving to the launch site from a munitions factory near Pyongyang, Seoul's Yonhap News Agency said, citing South Korean government officials. "It can be analyzed that the North is proceeding with missile launch preparations in stages," the source was quoted as saying.

Some analysts say the missile launch could take place before the end of this month, to mark Kim Jong Il's birthday on Feb. 16, Clinton's visit to Seoul next week, or the first anniversary of South Korean President Lee Myung-bak's inauguration on Feb. 25.

Seoul's Foreign Minister Yu Myung-hwan warned North Korea against launching a missile. "Such a behavior will lead only to its isolation" by triggering tougher sanctions from the international community, he told a news briefing.