Speaking on Thursday, Milei challenged political and economic systems based on state intervention, arguing that socialism and fascism shared similarities in how they exercised control over individuals.

"Both doctrines concentrate control over individual decisions in the hands of a minority. And they make economic dependency an instrument of political domination," the Argentine said.

His comparison placed two historically and ideologically different political traditions in the same category.

The summit also brought Milei face-to-face with Sanchez for the first time since the Argentine president publicly described the Spanish leader as a "dictator", "delinquent" and "thief".

Their meeting was marked by a cool reception following the recent exchange of criticism.

During his address, Milei presented Argentina as an example of a shift towards liberal economic policies in Latin America .

He also pointed to election results in Chile, Colombia and Peru, describing them as evidence of what he called a "democratic rebellion against paternalism and the abuse of power".

Beyond his criticism of the left, Milei used the summit to raise Argentina's longstanding sovereignty dispute with the United Kingdom over the Malvinas Islands, known in Britain as the Falkland Islands.

He urged Ibero-American countries to support renewed negotiations with London over the territory.

The Argentine president also questioned hydrocarbon exploration and exploitation projects in the disputed archipelago.