North Korea has angrily denounced a United Nations resolution condemning its missile tests and said it would build up its military arsenal.
North Korea had been observing a missile-test moratorium before July
The country's foreign ministry described the resolution as the product of a hostile American policy and said Pyongyang would not be bound by it.
North Korea would, it said, "bolster its war deterrent" in every way.
South Korea has urged Pyongyang to order a moratorium on missile tests and return to six-party nuclear talks.
The UN resolution demands that North Korea suspend its ballistic missile programme, and bars all UN member states from supplying North Korea with material related to missiles or weapons of mass destruction.
It was passed unanimously by the Security Council after being revised to drop any mention of Chapter Seven of the UN Charter, which is legally binding and can authorise sanctions or even military action.
China had otherwise threatened to veto it.
The resolution was tabled by Japan after North Korea test-fired seven missiles including a long-range Taepodong-2, believed capable of reaching Alaska.
Japan had produced its draft resolution for the 15-member Security Council just days after the tests on 4 and 5 July.
It underlines the need for North Korea "to show restraint and refrain from any action that might aggravate tension", and calls for Pyongyang to return to the six-nation talks over its nuclear programme.
Japanese Foreign Minister Taro Aso said the Security Council had acted "swiftly and robustly in response to [North Korea's] reckless and condemnable act".
The UK and US ambassadors to the UN described the resolution as strong and binding.
US Ambassador John Bolton said it had sent "an unequivocal, unambiguous and unanimous message to Pyongyang".
He said that if North Korea did not comply with the resolution, the council could consider further action.