Brazilian President Dilma Rousseff on Wednesday said Pope Francis told her he intended to take part in World Youth Day in Rio de Janeiro in July, although the Vatican did not confirm this.
Rousseff was received by the Argentine pope in his private library in the Vatican, a day after his informal inauguration on St Peter's Square.
Brazil is the country with the highest number of Catholics in the world.
"He said he hoped for a high number of young people," Rousseff said after meeting the first Latin American pontiff, who is also the first non-European pope in nearly 1,300 years.
Vatican spokesman Federico Lombardi said only that Rousseff had asked the pope to come to the event.
World Youth Day has been scheduled for months and Francis's predecessor Benedict XVI had been expected to attend, before he stunned the world by announcing last month he was resigning.
Rousseff, a former Marxist guerrilla who took office on January 1, 2011, was quoted by state news agency Agencia Brazil as saying that she and the pope also discussed the fight against poverty and drugs.
"This is a pope who speaks to the most fragile, to young and old, and to anyone who needs help," she said.
Francis's first audience with a world leader was with compatriot President Cristina Kirchner of Argentina on Monday, a day before his inauguration.