In Friday's vote at the Security Council, nine countries voted in favor of sanctions against the Robert Mugabe's government. The United States had proposed an arms embargo on Zimbabwe, and a travel ban along with financial restrictions on Mugabe and his closest allies.
Explaining the Russian position, the country's UN envoy, Vitaly Churkin, said: "The proposed draft is nothing other than interference by the Security Council in the internal affairs of a state, which contravenes the UN statutes."
"In recent times the positions of certain member states of the Security Council have more and more clearly shown a drive to take the council beyond its charter prerogatives, and beyond supporting international peace and security. We believe such practices to be illegitimate and dangerous, threatening to upset the whole UN system," he said.
South Africa, Libya and Vietnam also voted against the U.S. proposals, while Indonesia abstained.
The U.S. envoy to the UN, Zalmay Khalilzad, said Russia was reneging on its position expressed at this week's Group of Eight summit in Japan, which "raises doubts about its reliability as a G8 partner."
In the lead-up to the June presidential election runoff in Zimbabwe, opposition leader Morgan Tsvangirai dropped out of the race, citing death threats and beatings of supporters, and took refuge in the Dutch Embassy in Harare.
Tsvangirai had won the first election round in March, but without a sufficiently large majority to secure victory. Mugabe campaigned in the re-run as the sole candidate.
The opposition said on Friday that a total of 113 of its activists have been killed in election violence since March.