Russia and China have vetoed a US push for the United Nations Security Council to call for free and fair presidential elections in Venezuela and unhindered aid access.
The US draft resolution garnered the minimum nine votes, forcing Russia and China to cast vetoes.
South Africa also voted against the text, while Indonesia, Equatorial Guinea and Ivory Coast abstained.
Russia and the United States have been at loggerheads over a US-led campaign for international recognition of Juan Guaido, the Venezuelan opposition leader and head of the country's elected National Assembly, over President Nicholas Maduro.
Guaido last month declared himself the interim head of state.
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"We are seriously concerned about the fact that today's meeting may be exploited as a step for preparations of a real, not humanitarian, intervention ... as a result of the alleged inability of the Security Council to resolve the situation in Venezuela," Russian UN Ambassador Vassily Nebenzia said.
US President Donald Trump says all options are on the table in dealing with Venezuela, although US special envoy Elliott Abrams has denied Russian accusations Washington is preparing to intervene militarily.
Ahead of the Security Council vote on Thursday, French UN Ambassador Francois Delattre, in support of the US resolution, said it "does not represent a legal basis for a use of force nor an attempt to undermine the sovereignty of Venezuela".
The United States and dozens of other nations have recognised Guaido as Venezuela's legitimate president but Maduro still controls the military, state institutions and oil company Petroleos de Venezuela SA, which provides 90 per cent of the country's export revenue.
"The Venezuelan affairs should be decided by the Venezuelan people," China's Deputy UN Ambassador Wu Haitao said.
The United States targeted Venezuela's government with new sanctions on Monday and called on allies to freeze the assets of state-owned PDVSA after deadly violence blocked humanitarian aid from reaching the country over the weekend.
Secretary of State Mike Pompeo says Washington is still working on plans to get humanitarian aid delivered to Venezuela.
