The 2014 World Cup must be held in Brazil, FIFA secretary general Jerome Valcke said on Friday, one day after more than one million people marched in protests across the country.
"The Confederations Cup is taking place in Brazil and the World Cup must be held in Brazil," he told local media ahead of a meeting bringing together FIFA, the Brazilian Football Confederation and the World Cup's Local Organizing Committee.
"There is no plan B," he insisted.
Earlier on Friday, world football's governing body FIFA said that it has no plans to scrap the Confederations Cup currently under way, and that no team wants to pull out despite the huge protests rocking Brazil.
"At no stage has FIFA considered or discussed abandoning the Confederations Cup with the local authorities," FIFA media chief Pekka Odriozola said. "We are monitoring the situation with the authorities."
"We support the right of free speech," he added. "We condemn violence."
Mass demonstrations, which have sometimes turned violent, are taking place as Brazil is hosting eight teams from around the world for the Confederations Cup, a dry run for next year's World Cup being held in six host cities.
Many Brazilians are angry that bills for preparing the World Cup and the 2016 Summer Olympics are running to billions of dollars while many say they are not benefiting a country saddled with deep social inequality and inadequate social services.
On Thursday, two FIFA minibuses and the facade of a hotel housing some FIFA staff were stoned by some demonstrators before a Confederations Cup match in which Uruguay edged Nigeria 2-1.