China condemned a Japan-sponsored U.N. resolution to slap sanctions on North Korea over its missile tests on Tuesday, calling it an over-reaction that would split the Security Council. The statement came as a top U.S. envoy flew into Beijing, seeking a briefing on China's urgent efforts to resolve the crisis by diplomatic means. The U.N. Security Council delayed a vote overnight on the resolution to impose sanctions on the isolated state to allow time for a high-level Chinese delegation to talk to Pyongyang. "The Chinese side thinks the concerned draft resolution is an over-reaction. If approved, it will aggravate contradictions and increase tension," Foreign Ministry spokeswoman Jiang Yu told a news conference. "It will hurt efforts to resume six-party talks as well as lead to the U.N. Security Council splitting." Chinese President Hu Jintao told visiting North Korean parliamentarian Yang Hyong Sop that China opposed any action that would stoke tension on the Korean peninsula. State media said he urged all parties to take steps conducive to peace and stability.