Argentina's President Javier Milei has fired his foreign minister Diana Mondino after the country unexpectedly voted to end the US embargo on Cuba at the United Nations, marking one of the highest-level departures in his administration.

The sudden dismissal has exposed growing fissures within Milei's administration, as internal power struggles and diplomatic missteps culminate in a high-profile departure.

The immediate trigger for Mondino’s exit was Argentina's vote at the UN General Assembly urging the “necessity of ending the economic, commercial and financial embargo imposed by the United States of America against Cuba,” a position that stood at odds with Milei's stark anti-communist stance. The resolution passed on October 30 with 187 votes in favour, with only the United States and Israel opposing. It renewed a demand the Assembly had made annually since 1992.

Yet diplomatic sources suggest the Cuba vote was merely the final act in a months-long erosion of Mondino's authority. The foreign ministry had been systematically stripped of key responsibilities, with the presidential office, de facto led by Milei's sister Karina, taking control of the investment agency — the ministry's primary source of operational funds for trade missions and commercial fairs.

The president's office swiftly announced Gerardo Werthein, the current ambassador to Washington and a prominent business figure, as Mondino's replacement. Werthein brings substantial private sector credentials as a leader within one of Argentina's most powerful conglomerates and serves as a vice-president of the International Olympic Committee.

Mondino's tenure had been marked by controversy from the start. Despite her role as an early campaign ally who helped shore up Milei's international credibility, she found herself increasingly isolated within the administration. Sources close to the government report she had no direct communication channel to the president and was notably absent from recent presidential foreign trips.

Her position was further compromised by a series of diplomatic incidents, including controversial remarks about China during an official visit and a recent ministerial communiqué that referred to the "Falkland Islands" rather than the Argentine designation "Malvinas" — a highly sensitive issue in Argentine politics.

The administration has moved to frame the minister's departure as a resignation, but palace sources indicate it formed part of a broader strategy to assert control over the diplomatic corps. A fortnight ago, Milei dismissed the country's UN ambassador, Ricardo Lagorio, and issued an ultimatum to diplomatic staff, demanding they align with his political vision or "step aside."

In an unprecedented move, the government announced plans to audit career diplomats to identify those promoting what it terms "agendas that are enemies of freedom." The announcement has sent shockwaves through Argentina's diplomatic establishment, with concerns rising about a potential purge of career officials.

Mondino's dismissal marks the second high-level departure in Milei's administration, following the earlier exit of Cabinet chief Nicolás Posse. It comes at a delicate time for Argentina's international relations, as the country navigates complex relationships with major trading partners while maintaining the firebrand libertarian leader’s positions.

The timing of the Cuba vote has particularly complex implications for Argentina's foreign policy. Ministry sources suggest that while opposing the US and Israel was diplomatically awkward, Cuba's support could prove crucial for future UN resolutions regarding the Malvinas sovereignty dispute — highlighting the practical constraints on Milei's ideological foreign policy.

Werthein's appointment signals a potential shift toward a more pragmatic approach, though the president's office has reiterated its commitment to opposing what it calls “dictatorial regimes.” The transition comes as Argentina seeks to balance Milei's strong pro-Israel stance — which has isolated it from regional neighbours who have withdrawn ambassadors from Tel Aviv — with its broader diplomatic and trade interests. This has most remarkably led to a change of tune towards Beijing, now identified by Milei as an interesting trading partner after being initially dubbed a “cruel communist dictatorship” with whom there would be no business whatsoever.

The shake-up at the foreign ministry underscores a wider pattern in Milei's erratic governance style, where ideological purity and personal loyalty appear to trump traditional diplomatic considerations. With the announcement of diplomatic audits and further concentration of power in the presidential office, Argentina's foreign policy apparatus faces its most significant overhaul in recent memory.