China has released a statement condemning all forms of cyber terrorism in the wake of the Sony Pictures hack, but without any direct mention of the leak or US claims of North Korean involvement.

Chinese Foreign Minister Wang Yi revealed that he spoke of Beijing's opposition to cyber attacks in talks with US Secretary of State John Kerry.

He "reaffirmed China's relevant position, emphasising China opposes all forms of cyberattacks and cyber terrorism", the foreign ministry in Beijing said in a statement. There was no mention of North Korea's alleged activities with regard to Sony Pictures.

"(China) opposes any country or individual using other countries' domestic facilities to conduct cyberattacks on third-party nations," said the statement.

China represent's North Korea's sole major ally in world politics and Beijing's diplomatic relations with the pariah state would be central to any American efforts to punish Kim Jong-un's regime in the wake of the Sony Pictures hack.

North Korea has vehemently denied any involvement in the hack but has admitted that the hackers may be supporters of the country.

"We do not know who or where they (the hackers) are but we can surely say that they are supporters and sympathisers with the DPRK (Democratic People's Republic of Korea)," said a commentary on KCNA, the country's state news agency.

US President Barack Obama said that he did not believe that the Sony leak was an act of war but that Washington would respond accordingly.

"No, I don't think it was an act of war," he told CNN. "I think it was an act of cyber vandalism that was very costly, very expensive. We take it very seriously. We will respond proportionately."