President Hugo Chavez vowed that Venezuela will win a seat on the UN Security Council, but accused Washington of waging "a dirty war" against his country in a last ditch effort to prevent it from defeating US-backed Guatemala.
"Go forth with the bayonet! Venezuela is going the Security Council," Chavez said on Sunday, encouraging Venezuela's ambassador to the United Nations, Francisco Arias Cardenas, on the eve of the vote.
Chavez, a close ally of Cuban leader Fidel Castro, has repeatedly warned that Washington could attempt to drag out the October 16 vote for weeks or even years if neither candidate garners the required two-thirds majority.
The United States is supporting Guatemala and hopes to stop Chavez from winning a seat on council - a platform to voice opposition to what he calls Washington's "imperialist" policies.
The US government warns that Chavez, whose government maintains friendly ties with North Korea and Iran, would be a disruptive force on the 15-member council.
Both Venezuela and Guatemala say they have a majority in the 192-member UN General Assembly ahead of today's secret vote.
If neither side gains two-thirds of the vote after repeated ballots, the 33-nation Latin American group could offer another candidate.
Chavez argues that is what US officials want to see happen.
Countries are not obliged to make known their preference, though much of the Caribbean and South America have voiced support for Venezuela.
The 53 countries in the African group are expected to tilt toward Venezuela, while Asia's 54 nations are said to be split.