Argentina's libertarian president, Javier Milei, is trying to downplay the budget crisis in public universities as normal, in a polemic with his left-wing opponents, who are influential in university spaces.

But at the elitist University of Buenos Aires (UBA) the walls are turning black and the elevators and air conditioning stopped working in some buildings last week.

Professors are teaching classes of 200 people without microphones or projectors because the public university - among the best in Latin America - can't pay the electricity bill.

"This is an unthinkable crisis," said Valeria Anón, a 50-year-old literature professor, at a demonstration against Milei's austerity measures in downtown Buenos Aires on Tuesday, attended by thousands of people. "I feel very sad for my students and for myself," she added.

In his policy to achieve a budget surplus, Milei is cutting spending across the board, closing ministries, cutting funding for cultural centers, firing civil servants and eliminating subsidies.

On Monday, Milei said that Argentina had achieved its first quarterly surplus since 2008.

"We are doing the possible and the impossible, even with the majority of politicians, unions, the media and most economic agents against us," he said during a televised address.

A crowd of students and university professors left the UBA on Tuesday in protest, joining thousands of other demonstrators in the center of the capital. Some private schools closed in solidarity. The protests have spread to other Argentine cities.

A sign of the more generalized ideological battle taking place, trade unionists and supporters of left-wing parties also filled the streets.

Since July, when Argentina's budget year began, the 200-year-old UBA has only received 8.9% of the funds it was budgeted for, while facing annual inflation of 290%.

The university has already said that it is finding it very difficult to keep the lights on and guarantee basic services in the university hospitals, which have reduced their capacity.

After declaring a state of budgetary emergency, the UBA warned last week that, without a rescue plan, it would close in the coming months, interrupting the studies of 380,000 students.

A statement that came as a shock to Argentinians, who consider a free, quality university education to be a natural right. The UBA has a prestigious intellectual tradition, having produced five Nobel Prize winners and 17 Argentine presidents.