North Korea, after its artillery attack on the South this week, warned Friday that plans for a US-South Korean naval exercise bring the peninsula 'closer to the brink of war'. The hardline communist regime on Tuesday fired shells and rockets at the South Korean island of Yeonpyeong, killing four people. It later claimed it was retaliating after South Korea had staged military exercises. The USS George Washington carrier strike group, based in Japan, was Friday heading for waters west of the Korean peninsula where the US and South Korea plan four days of naval exercises in the Yellow Sea from Sunday. US Forces Korea said in a statement Wednesday the drill had been planned well before North Korea's 'unprovoked artillery attack' but it demonstrated the US 'commitment to regional stability through deterrence'. Pyongyang's state-run Korean Central News Agency, in an article Friday on the planned war games, attacked 'the US imperialists and south Korean puppet war- like forces' for what it called an exercise in 'sabre-rattling'. 'The situation on the Korean Peninsula is inching closer to the brink of war due to the reckless plan of those trigger-happy elements to stage again the war exercises targeted against the DPRK,' it said, using the country's official name, the Democratic People's Republic of Korea. US Forces Korea said in its statement Wednesday that the exercise is defensive in nature. 'While planned well before yesterday's unprovoked artillery attack, it demonstrates the strength of the Republic of South Korea-US alliance and our commitment to regional stability through deterrence,' it said. 'It is also designed to improve our military interoperability.' The statement said that the US Navy 'routinely operates in the waters off the Korean peninsula and has conducted numerous operations and exercises in this area.' North Korea's key ally China said Thursday it opposed the US-South Korea war games. 'We have taken note of relevant reports and express concern,' foreign ministry spokesman Hong Lei told reporters when asked about the exercises. 'We oppose any act that undermines peace and stability on the peninsula.' China has previously come out strongly against such exercises in what it sees as its backyard, saying they risk exacerbating tensions. fz/sm/bsk 