The UN Security Council ordered expanded sanctions Tuesday against North Korea for a banned rocket launch, triggering a defiant pledge by Pyongyang to bolster its nuclear deterrent.

The Security Council added North Korea's state space agency, a bank, four trading companies and four individuals to the UN sanctions list, and threatened "significant action" if the North stages a nuclear test.

The resolution, proposed by the United States, was passed unanimously by the 15-nation council, including North Korea's only major ally, China.

Pyongyang insists its December 12 rocket launch was a peaceful, scientific mission aimed at putting a satellite in space.

The UN resolution condemned it as a disguised ballistic missile test that violated existing sanctions imposed after the North's nuclear tests in 2006 and 2009.

The US government had sought a tough UN response to Pyongyang, as China tried to shield its ally from a new set of sanctions.

US Ambassador Susan Rice said the resolution was a sign that North Korea will have "an increasingly steep price" to pay if it chooses confrontation.

China's UN envoy Li Baodong stressed that sanctions alone would fail unless they were supplemented by a concerted diplomatic effort to engage Pyongyang in negotiations.

The Security Council demanded that the North suspend "all activities related to its ballistic missile program" and "abandon all nuclear weapons and existing nuclear programs in a complete, verifiable and irreversible manner."

It also expressed "its determination to take significant action in the event of a further DPRK (North Korea) launch or nuclear test."

The Korean Committee for Space Technology, the government agency that organized last month's rocket launch, topped the list of new bodies sanctioned.

The list also included Bank of East Land, which the resolution said had been used to transfer funds to "in a manner that circumvents sanctions" and had dealt with banks in Iran that also face UN sanctions.

Korea Kumryong Trading Corp., Tosong Technology Trading Corp., Korea Ryonha Machinery Joint Venture Corp. and Leader International (based in Hong Kong) were also added to the list.

All were accused of procuring equipment for North Korea's nuclear and missile development or of exporting and dealing in arms. The resolution deplored the North's use of "bulk cash" to avoid sanctions.

The four individuals put on the list were all involved in North Korea's technology development or bank officials.

"This resolution demonstrates to North Korea that there are unanimous and significant consequences for its flagrant violation" of previous resolutions, Rice told reporters.

North Korea's foreign ministry quickly slammed the council and hinted that a new nuclear test could be planned.

"We flatly reject and condemn the UN Security Council's extremely unfair resolution," said a ministry statement.

"We will take physical actions aimed at expanding and strengthening our self-defensive military forces, including nuclear deterrence."

Last month, a US think-tank used satellite photos to suggest the North has repaired extensive rain damage at its nuclear test site in the northeast of the country and could conduct a detonation at two weeks' notice.

China's Li said that despite his country's support for the resolution, the Council had to be "prudent, measured, proportionate, conducive to peace and stability," urging new efforts to "avoid the escalation of tension."

China has been trying to revive moribund six-nation talks on the North's nuclear program.

But North Korea's foreign ministry said there would be "no dialogue to discuss denuclearization of the Korean peninsula."

Analysts said the expanded sanctions would have a limited impact, but stressed the importance of China's backing for the resolution.

"North Korea would collapse without Chinese support. So when China backs sanctions, even if they aren't that tough, it's significant," said Robert Kelly, professor of Political Science and Diplomacy at Pusan National University.

South Korea, a temporary member of the council since January 1, welcomed the resolution, as did Japan and UN leader Ban Ki-moon.