While the US government hailed the resignation of Evo Morales, Fernández accused the country of reverting to the 1970s, a period in which the nation aided 'military interventions against democratically elected governments' throughout Latin America.
United States President Donald Trump hailed the resignation of Bolivia's leftist leader Evo Morales Monday, calling it a sign to "illegitimate" regimes and praising the role of the country's military.
"These events send a strong signal to the illegitimate regimes in Venezuela and Nicaragua that democracy and the will of the people will always prevail," Trump said, referring to two other leftist Latin American nations targeted by his administration.
Trump said that the resignation of Morales, Bolivia's first indigenous leader who was seeking a fourth term despite a constitutional prohibition, was a "significant moment for democracy in the Western Hemisphere."
"After nearly 14 years and his recent attempt to override the Bolivian Constitution and the will of the people, Morales' departure preserves democracy and paves the way for the Bolivian people to have their voices heard," Trump said in a statement.
"The United States applauds the Bolivian people for demanding freedom and the Bolivian military for abiding by its oath to protect not just a single person, but Bolivia's constitution," he said.
Argentina's president-elect Alberto Fernández responded swiftly and strongly just hours later Tuesday morning.
"I won't share what was said by the United States State Department. Here, there is no victorious army and it is not true that democracy has been guaranteed. If anything, it's been impeded," he said during an interview with Radio 10.
"In my judgement, the United States has reverted back decades and returned to the worst parts of the 1970s, when it endorsed military interventions against democratically elected governments," Fernández said.
Morales quit on a fast-moving day of events Sunday after security forces pulled through support for him in the face of public protests and a report by the Organisation of American States that pointed to irregularities in voting last month.
A US State Department official rejected accusations that the Bolivian military staged a coup, calling it a "false narrative."
"You have surely seen statements by Morales and his supporters calling him the victim of a coup, despite the fact that what all these events clearly show is the Bolivian people have simply had enough of a government ignoring the will of its voters," the official said.
He nonetheless voiced hope that the transition would be civilian-led and said the US was not picking a favorite.
The official said that Bolivian legislators should formally accept Morales' resignation and call new elections.
"We call on the National Assembly to convene, to provide the quorum required and to determine a constitutional transition to new elections as soon as possible," the official said on condition of anonymity.
A formal designation of a coup would require the United States to cut most aid to Bolivia, which had uneasy relations with the US under Morales, especially over his championing of indigenous coca farmers.