By Clinton Porteous
BBC News, Santiago
Washington will continue to back a Mexican candidate to head the Organisation of American States, Condoleezza Rice has said.
Ms Rice acknowledged the leadership process has been divisive
The secretary of state restated the US position in talks on the regionally divisive issue with Chilean President Ricardo Lagos in Santiago.
A new leader to the post, vacant since October, will be elected on Monday.
Earlier this month, candidates from Mexico and Chile were deadlocked on 17 votes each after five rounds of voting.
Traditionally, the US-backed candidate wins the leadership of the organisation, but it might not be the case this time.
Towards the end of her first tour of South America, Ms Rice was confronted with the tricky issue of the upcoming leadership ballot.
The US originally backed a candidate from El Salvador, but after he withdrew from lack of support, it switched to Mexico.
The Mexican candidate, Foreign Minister Luis Ernesto Derbez, is seen as more conservative than Chile's Interior Minister Jose Miguel Insulza, who is a member of the socialist party.
More importantly, the region appears to be splitting along geographic lines.
In the first ballot, most of South America and the Caribbean supported the Chilean candidate, while Central and North America backed Mexico.
Ms Rice reiterated US support for the Mexican candidate during a news conference in Santiago, but also praised the Chilean nomination.
She acknowledged that the leadership process had been divisive.
She said: "Our task has to be to talk, to discuss, how we might move forward on a basis that once again brings us to unity."
Ms Rice is visiting Chile for the first time as secretary of state, but it appears her tour could be dominated by last-minute lobbying for the next OAS secretary general.