After participating in Mercosur trade talks in Buenos Aires, Brazilian President Luiz Inácio Lula da Silva visited former Argentine President Cristina Fernandez de Kirchner on Thursday at her apartment in Buenos Aires, where she is serving a six-year sentence for corruption.

Kirchner called Lula’s visit “a political act of solidarity,” in a post on X following the meeting, and said that the Brazilian leader had also been a victim of political persecution. In 2017, Lula faced a corruption conviction for which he served 19 months in prison.

Lula, a leftist leader, did not meet privately with Argentine right-wing libertarian President Javier Milei, who has called him a “communist” and “corrupt.” During the trade summit and Lula’s first visit to Argentina since Milei took office, Brazil took up the rotating presidency of the Mercosur bloc.

Kirchner was president of Argentina from 2007 to 2015 and last month began serving a sentence for participating in a fraud scheme that steered public road work projects to a close ally while she was president. The sentence, upheld in June by the country’s Supreme Court, also bars Fernandez from holding office.

In recent days, supporters of Kirchner have rallied outside of her apartment, hoping to catch a glimpse of the prominent opposition figure when she appears on her balcony.

After the Supreme Court upheld Kirchner’s sentence, Lula said on social media site X that he called Kirchner to express support and spoke to her “about the importance of staying strong in this difficult moment.”