The South American nations and the US issued a joint statement calling on Bolivia to cooperate with the Organization of American States (OAS) to ensure "transparent" and "credible" vote count and to hold a second round of presidential elections.
"Argentina, Brazil, Colombia and the United States believe that the Bolivian people have the right to choose their leaders in free and fair elections," the statement reads. "We urge Bolivian electoral authorities to work with the Organization of American States Electoral Observation Mission to guarantee a transparent and credible vote-counting process."
The statement by the four nations calls on Bolivia to hold a second round of elections "in the event that the EOM is unable to verify the results of the first round."
In his address, Trujillo said that the US suspects Bolivian electoral authorities of vote manipulation, citing a temporary shutdown of TREP, the Bolivian electronic vote reporting system. The Supreme Electoral Court of Bolivia explained Thursday that TREP was shut down to avoid confusion with different results reported as a result of a manual vote count. According to the Court, the manual vote, while slower, was shown to be significantly more accurate.
Earlier this week, opposition leader Carlos Mesa denounced the preliminary vote results as a fraud. His calls contributed to violent protests in which protesters set fire to electoral offices in several Bolivian cities.