UNITED NATIONS - A US-backed push to impose an arms embargo on Zimbabwe and sanction President Robert Mugabe and his top advisers over the country's disputed presidential election came to a grinding halt Friday when Russia and China, exercising a rare double veto, quashed an American resolution in the UN Security Council. South Africa, which is mediating Zimbabwe's political crisis, Libya and Vietnam also voted against the draft while Indonesia abstained. Voting with the United States were Britain, France, Belgium, Italy, Panama, Bukina Faso, Croatia and Costa Rica. Russian and Chinese envoys said UN sanctions amounted to unwarranted interference in Zimbabwe's domestic affairs and would have threatened preliminary talks between Mugabe's government and representatives of his chief political rival, Morgan Tsvangirai, to resolve the country's crisis. Russia's U.N. ambassador Vitaly Churkin criticized the US initiative as a scheme to use the U.N. Security Council-which deals with threats to international peace and security-to punish its political opponents. "We have seen an ever more obvious attempt to take the council beyond its prerogative," Churkin said. "We consider such action to be illegitimate and dangerous. We intend to continue countering this trend." China echoed that argument but also expressed concern about whether the sanctions would impede mediation efforts by South Africa. "We feel that the important thing is for the political parties to get together to discuss this issue seriously to sort out their differences," the Chinese ambassador, Wang Guangya, said before rejecting the resolution. "It will interfere with the negotiating process and lead to the further deterioration of the situation." The United States and Britain denounced the veto, saying it would hurt efforts to bring democracy to Zimbabwe. Expressing his disappointment at the veto, US Ambassador Zalmay Khalilzad said, "China and Russia have stood with Mugabe against the people of Zimbabwe ... for reasons that we think are not borne out by the facts on the ground". "The U-turn on the Russian position is particularly surprising and disturbing," he said, noting that a few days ago, the Russian Federation was supportive of a statement adopted at the Group of Eight meeting in Japan expressing "grave concern" about the situation in Zimbabwe. "The Russian performance here today raises questions about its reliability as a G-8 partner," Khalilzad added. Churkin, the Russian ambassador, reacted forcefully to a similar charge by Britain's UN ambassador, John Sawers. The Russian envoy said it was "irresponsible and factually incorrect" to claim Russia committed to UN sanctions at the G-8 summit. He said the statement made no mention of Security Council action. The United States and Britain mustered the nine votes required for the resolution to pass in the 15-nation council. The measure would have imposed a travel ban and asset freeze on Mugabe and 13 senior military and civilian advisers. South Africa led opposition to the resolution, arguing that efforts to punish Mugabe would undercut efforts by South African President Thabo Mbeki to mediate a power-sharing agreement between the Zimbabwean government and opposition-an argument that even some of Mugabe's African critics supported.  "The political option should take precedence over the punitive option," Tanzania's UN ambassador, Augustine  Mahiga, told the council. But Khalilzad countered that Mbeki is "working hand-in-glove" with Mugabe. Khalilzad said that Mugabe has used violence to fragment the opposition while Mbeki has used diplomacy to do the same.