N Korea threatens US as cyberattacks row deepens

PYONGYANG, Dec 22 (agencies):  North Korea has threatened unspecified attacks on the US in an escalation of a war of words following the Sony Pictures cyber-attacks.
In a fiery statement, the North warned of strikes against the White House, Pentagon and "the whole US mainland".
North Korea denies US claims it is behind cyber-attacks linked to a film that features the fictional killing of its leader Kim Jong-un. North Korea has a long history of issuing threats against the US.
The latest statement comes days after the US formally accused the North of orchestrating a massive cyber attack on Sony Pictures.
"The army and people of the DPRK (North Korea) are fully ready to stand in confrontation with the US in all war spaces including cyber warfare space," a long statement carried by the official Korean Central News Agency said.
"Our toughest counteraction will be boldly taken against the White House, the Pentagon and the whole US mainland, the cesspool of terrorism, by far surpassing the 'symmetric counteraction' declared by Obama."
It accused President Obama of "recklessly making the rumour" that North Korea was behind the Sony attack.
It also said it "estimates highly the righteous action" taken by the hackers of Sony, although it is "not aware of where they are".
China said on Monday it opposed all forms of cyberattacks but there was no proof that North Korea was responsible for the hacking of Sony Pictures, as the United States has said.
North Korea has denied it was to blame and has vowed to hit back against any U.S. retaliation, threatening the White House and the Pentagon. The hackers said they were incensed by a Sony comedy about a fictional assassination of North Korean leader Kim Jong Un, which the studio has pulled.
China made no reference to calls by the United States for joint action with it and other countries to counter any similar cyberattacks.
"Before making any conclusions there has to be a full (accounting of) the facts and foundation," foreign ministry spokeswoman Hua Chunying said. "China will handle it in accordance with relevant international and Chinese laws according to the facts."
She said Chinese Foreign Minister Wang Yi "reaffirmed China's relevant position, emphasizing China opposes all forms of cyberattacks and cyber terrorism" in a conversation with U.S. Secretary of State John Kerry on Sunday.
China is North Korea's only major ally, and would be central to any U.S. efforts to crack down on the isolated state. But the United States has also accused China of cyber spying in the past and a U.S. official has said the attack on Sony could have used Chinese servers to mask its origin.
South Korea, which is still technically at war with North Korea, said computer systems at its nuclear plant operator had been hacked and non-critical data stolen, but there was no risk to nuclear installations or reactors.
"It's our judgment that the control system itself is designed in such a way and there is no risk whatsoever," Chung Yang-ho, deputy energy minister, told Reuters by telephone.
He made no mention of North Korea and could not verify messages posted by a Twitter user claiming responsibility for the attacks and demanding the shutdown of three aging nuclear reactors by Thursday.
U.S. President Barack Obama and his advisers are weighing how to punish North Korea after the FBI concluded on Friday it was responsible for the attack on Sony.
It was the first time the United States had directly accused another country of a cyberattack of such magnitude on American soil and set up the possibility of a new confrontation between Washington and Pyongyang.