China warns against Korea escalation

North Korea has announced that it is cancelling a hotline and a nonaggression pact with South Korea while reiterated past threats in anger over a UN Security Council vote to impose more sanctions on the country for its third nuclear test.

China, the North's only major ally, said all sides should continue to talk and avoid "further escalation".

Pyongyang has reacted angrily to another round of sanctions imposed by the UN over its recent nuclear test.

The sanctions restrict luxury goods imports and banking activities.

Beijing provides fuel, food and diplomatic cover to Pyongyang.

It has repeatedly voted in favour of UN sanctions imposed over the nuclear programme, but enforcement of the measures in China is patchy.

Hua Chunying of China's foreign ministry told a news conference on Friday: "China and North Korea have normal country relations. At the same time, we also oppose North Korea's conducting of nuclear tests.

"China calls on the relevant parties to be calm and exercise restraint and avoid taking any further action that would cause any further escalations."

Chinese and US officials drafted the UN resolution passed on Thursday.

It contains similar measures to earlier resolutions, but the US said it had significantly strengthened the enforcement mechanisms.

A statement the North issued on Friday said the country would retaliate with "crushing strikes" if enemies intruded into its territory.

It also said that North Korea was voiding past inter-Korean nuclear disarmament statements.

North Korea previously said it was cancelling a hotline with the US and the armistice that closed the Korean War in 1953.

Thursday's Security Council resolution will tighten financial restrictions on North Korea and crack down on its attempts to ship and receive banned cargo in breach of UN sanctions.

The US-drafted statement, which was approved unanimously by the 15-nation council, was the product of three weeks of negotiations between the US and China after North Korea's February 12 nuclear test.

Ban Ki-moon, the UN secretary-general who is a former South Korean foreign minister, welcomed the council's move, saying in a statement that the resolution "sent an unequivocal message to [North Korea] that the international community will not tolerate its pursuit of nuclear weapons".

The two Koreas have signed a range of agreements over the years, including a 1991 pact on resolving disputes and avoiding military clashes.

However, analysts say the deals have had little practical effect.he North conducted its third nuclear test  in defiance of UN resolutions, and declared it had achieved progress in securing a functioning atomic arsenal.

Although North Korea boasts of nuclear bombs and pre-emptive strikes, it is not thought to have mastered the ability to produce a warhead small enough to put on a missile capable of reaching the US mainland.

It is believed to have enough nuclear fuel, however, for a handful of crude nuclear devices.

The North's unnamed foreign ministry spokesman also said it would be entitled to take military action as of March 11 when US-South Korea military drills move into a full-scale phase as it had declared the truce invalid.

It is the latest in an escalation of tough words from both sides of the armed Korean border this week as the UN Security Council deliberates a resolution to tighten financial sanctions and a naval blockade against the North.

North Korea, which held a mass military rally in Pyongyang on Thursday in support of its recent threats, has protested against the UN censures of its rocket launches.

It says they are part of a peaceful space programme and that the criticism is an exercise of double standards by the US.

In 2010, the North bombed South Korea's Yeonpyeong Island killing two civilians. It is widely accused of sinking a South Korean navy ship earlier in the year, killing 46 sailors.

North Korea was conducting a series of military drills and getting ready for state-wide war practice of an unusual scale, South Korea's defence ministry said earlier on Thursday.

South Korea and the US, which are conducting annual military drills until the end of April, are watching the North's activities for signs they turn from an exercise to an actual attack, a South Korean official said