UPDATE 3-N.Korea says will boost nuclear deterrent after UN rebuke
* North Korea space agency will now be blacklisted
* Council warns North against new nuclear test
* China called for cautious resolution on North Korea
* Pyongyang continues work on nuclear test site (Adds North Korean reaction, details)
UNITED NATIONS, Jan 22 (Reuters) - The U.N. Security Council on Tuesday unanimously condemned North Korea's December rocket launch and expanded existing U.N. sanctions, eliciting a vow from Pyongyang to boost the North's military and nuclear capabilities.
Even though the resolution approved by the 15-nation council does not impose new sanctions on Pyongyang, diplomats said Beijing's support for it was a significant diplomatic blow to Pyongyang.
The resolution said the council "deplores the violations" by North Korea of its previous resolutions, which banned Pyongyang from conducting further ballistic missile and nuclear tests and from importing materials and technology for these programs.
It also said the council "expresses its determination to take significant action in the event of a further DPRK (North Korean) launch or nuclear test."
North Korea reacted quickly, saying it would hold no more talks on the de-nuclearization of the Korean peninsula and would boost its military and nuclear capabilities.
"We will take measures to boost and strengthen our defensive military power including nuclear deterrence," its Foreign Ministry said in a statement carried by state news agency KCNA.
Six-party talks aimed at halting North Korea's nuclear program have involved North Korea, the United States, China, Japan, Russia and South Korea. They have been held intermittently since 2003 but have stalled since 2008.
South Korea says the North is technically ready for a third nuclear test, and satellite images show it is actively working on its nuclear site.
The U.N. resolution added six North Korean entities, including Pyongyang's space agency, the Korean Committee for Space Technology, and the man heading it, Paek Chang-ho, to an already existing U.N. blacklist.
CHINA WANTED 'CAUTIOUS RESOLUTION'
The firms and individuals will all face an international asset freeze, while Paek and the others blacklisted by Tuesday's resolution - the manager of the rocket launch center and two North Korean banking officials - will face a global travel ban.
In addition to the space agency, the council blacklisted the Bank of East Land, Korea Kumryong Trading Corp., Tosong Technology Trading Corp., Korea Ryonha Machinery Joint Venture Corp., and Leader (Hong Kong) International. The last, based in Hong Kong, is the North's main arms dealer, the resolution said.
U.S. Ambassador to the United Nations Susan Rice welcomed the resolution, describing it as introducing "new sanctions" against North Korea. "This resolution demonstrates to North Korea that there are unanimous and significant consequences for its flagrant violation of its obligations under previous resolutions," she said.
Other diplomats, however, said on condition of anonymity that saying the measures in Tuesday's resolution were new sanctions would be an exaggeration.
China said on Monday that the Security Council needed to pass a cautious resolution on North Korea, adding that this was the best way to ensure regional tensions did not escalate further.
Several diplomats said Beijing's decision to back the resolution sent a strong message to Pyongyang.
"It might not be much, but the Chinese move is significant," a council diplomat told Reuters. "The prospect of a (new) nuclear test might have been a game changer (for China)."
The United States had wanted to punish North Korea for the rocket launch with a Security Council resolution that imposed entirely new sanctions against Pyongyang, but Beijing rejected that option.
China is the North's only major diplomatic ally, although it agreed to U.N. sanctions against Pyongyang after North Korea's 2006 and 2009 nuclear tests.
December's successful long-range rocket launch, the first to put a satellite in orbit, was a coup for North Korea's young leader, Kim Jong-un.
North and South Korea are still technically at war because their 1950-53 conflict ended in a truce, not a treaty. (Additional reporting by Jumin Park and David Chance in Seoul; Editing by Mohammad Zargham and Philip Barbara)