UNITED NATIONS - The United States and China have struck a tentative deal on a draft UN Security Council resolution condemning North Korea for its December rocket launch, UN diplomats said on Friday, and Russia predicted it would be approved by the council. The resolution would not impose new sanctions, but would call for expanding existing UN sanctions measures against Pyongyang, the envoys said on condition of anonymity. They added that China's support for the move would be a significant diplomatic blow to Pyongyang. The 15-nation council could adopt the compromise resolution next week, they said. Russian UN Ambassador Vitaly Churkin confirmed the diplomats' comments in remarks quoted by the Russian state-run RIA Novosti news agency, saying that adoption was likely early next week. "I expect we will support it," RIA quoted Churkin as saying. "I don't expect that the UN Security Council members will have any serious problems (with the resolution)." "Our position is that the North Korean rocket launch is a violation of a U.N. Security Council resolution, so the council should react," he said. South Korea gave a guarded welcome to the tentative agreement. "Although we (the government) may not be fully satisfied with the outcome, (we) will have to welcome it if it can help restrain the unpredictable North's ultra-provocative action," said a government spokesman in Seoul, who declined to be named due to the sensitivity of the diplomatic negotiations. The two Koreas have been technically still at war since their 1950-53 conflict ended in a truce, not a treaty. The United States had wanted to punish North Korea with a U.N. Security Council resolution that imposed new sanctions against Pyongyang, but Beijing rejected that option. Beijing had wanted the council to merely issue a statement calling for the council's North Korea sanctions committee to expand the existing U.N. blacklists, diplomats said. The tentative deal, they said, was that Washington would forgo the idea of immediate new sanctions, while Beijing would accept the idea of a resolution instead of a statement, which makes the rebuke more forceful. Assuming the North Korea sanctions committee agrees to expand existing measures, the resolution will ultimately lead to more stringent sanctions against Pyongyang. "It might not be much but the Chinese move is significant," a council diplomat said. "The prospect of a (new) nuclear test might have been a game changer (for China)." After North Korea's April 2012 rocket launch, the council passed a so-called "presidential statement" that condemned the move and urged the North Korea sanctions committee to tighten the existing U.N. sanctions regime. The sanctions committee then blacklisted additional North Korean firms and broadened a list of items Pyongyang was banned from importing. Washington was determined not to use the same formula as last year, so it insisted that the council adopt a resolution, not a presidential statement as China had wanted. China is the North's only major diplomatic ally, though it agreed to U.N. sanctions against Pyongyang in the wake of North Korea's 2006 and 2009 nuclear tests.