Argentina's new president has firmly denied allegations by US prosecutors that Venezuela tried to illegally influence her election campaign.
President Chavez publicly endorsed Ms Fernandez's campaign
Cristina Fernandez de Kirchner said the charges were a "trashing operation" and she would let no-one pressure her.
Her comments came hours after four South Americans were charged in Miami with trying to cover up the scandal.
It began with the confiscation in Argentina in August of a briefcase containing $800,000 (£392,000).
The US authorities said their investigation demonstrated that the money was intended for Ms Fernandez's presidential campaign.
Venezuela has also rejected the accusations as a "fabricated scandal".
Correspondents say the affair is a political test for Ms Fernandez, who was sworn in as president on Monday.
In a speech in the capital Buenos Aires, President Fernandez said she remained undeterred in her desire to deepen relations with other Latin American countries and Venezuela in particular.
"This way of trying to operate in regional politics will not be successful," she said.
"They will not achieve results. This president may be a woman, but she will not allow anyone to pressure her."
Though she did not mention the US by name, correspondents say she was clearly referring to Washington.
The criminal complaint against the four men - three Venezuelans and a Uruguayan - said that "neither the true source nor the intended recipient of those cash funds had been disclosed".
But Assistant US Attorney Thomas Mulvihill said on Wednesday that an FBI recording showed that the money was destined for Ms Fernandez's campaign.
She was elected in October to take over the presidency from her husband Nestor.
Prosecutors say the defendants were undeclared agents and held meetings in Florida with a Venezuelan-American businessman, Guido Antonini Wilson, in an attempt to pressure him to hide the source of the money and its destination.
Mr Antonini Wilson was part of a delegation flown in to Buenos Aires by the Argentine government on a private jet in August.
Customs officials discovered the cash in his suitcase, and issued an extradition warrant when he fled to the US.
The businessman is not accused of any crime by the American prosecutors.