Kirchner, a senator and wife of current President Nestor Kirchner, was set to attend a meeting of Latin American and European leaders in Santiago, Chile, this week.
Some have speculated Cristina Kirchner canceled the trip due to Chilean President Michelle Bachelet's dwindling approval rating, La Nacion newspaper reported. In recent weeks, Bachelet's approval has dropped to 39 percent amid rising inflation and recent union protests.
Kirchner, meanwhile, is leading all contenders by a sizable margin ahead of this month's election.
2014: The Year in Music [PHOTOS]