President Mauricio Macri has said the government will allow opposing fans to attend the Copa Libertadores final between Boca Juniors and River Plate this month.
The decision is at odds with a 2013 ban on visiting fans at football matches that is aimed at reducing violence, and is expected to be a major security challenge for authorities. But Macri said on Friday the two-leg final between the arch-rivals will be "historic."
"It's also a good opportunity to show maturity, and that we're changing, and [football] can be played in peace," Macri said on his Twitter account.
Macri also said he has asked the Security Ministry to work closely with the Buenos Aires City government to ensure safety.
"We have to immortalise this historic opportunity with a full show and that means with visiting fans," Macri later told local Radio La Red.
Macri, a former president of Boca Juniors, recently expressed concerns about the possibility that the arch-rivals would face each other. He also said he preferred an Argentine team faced a Brazilian one in the final, but on Thursday he said he wished only for a "peaceful and harmonious" Boca-River duel.
The final will be at Boca's La Bombonera on November 10, and at River's El Monumental on November. 24. It ends just days before a summit of G-20 leaders in Buenos Aires.
Boca has a shot at tying Argentine club Independiente's record of seven titles. River will be going for its fourth South American crown, the last in 2015.