Presidency of Cristina Fernández de Kirchner and became president after his death. The transition from Néstor Kirchner to Cristina Kirchner was also the first time when a democratic head of state was replaced by his spouse, without involving the death of any of them. Néstor Kirchner stayed active in politics despite not being the president, and worked alongside Cristina Kirchner. The press developed the term ""presidential marriage"" to make reference to both of them at once. Some political analysts compared this type of government with a diarchy. During the first days of Fernández's presidency, Argentina's relations with the United States deteriorated as a result of allegations
Cristina Fernández de Kirchner opted instead to send a bill to Congress for the renationalization of YPF, privatized in 1993, blaming the Spanish company Repsol for the energy trade deficit. The bill was approved by the Chamber of Deputies by a 207-32 margin. It was criticized as an authoritarian move, as there was no negotiation with Repsol. As well, the Vaca Muerta oil field had been discovered by this time. However, YPF was unable to afford the costs to exploit the oil at the site, and the rights to drill at Vaca Muerta were sold to the Chevron Corporation. The costs of energy imports