Brazil's tournament organisers have faced headwinds since the country was tapped to host the World Cup in 2007.
Hundreds of thousands of Brazilian protesters took to the streets during the Confederations Cup last year over the high cost of the sporting extravaganza, as well as against taxes, inflation, corruption and poor public services.
Pele, a triple World Cup winner and special advisor of the World Cup organising committee, was in Mexico City giving a news conference when he was asked if the protests in Brazil could jeopardise the tournament.
"Yes, because I know that 25 percent of foreigners have already cancelled their trip to the country," he said.
Many fear protests will continue during the tournament from June 12 to July 13, after demonstrators angered by the cost of the event burned tyres last week near the $450 million Sao Paulo Corinthians Arena, the stadium where the tournament will open.
"That's one of the problems I pointed out six years ago. We knew that Brazil won the right to have the World Cup, and now one month before the Cup, stadiums there are not yet finished and have many problems, and that's a shame," Pele said.
The timing for the protests was not helping, he added.
"People should have demonstrated when Brazil was chosen to organise the World Cup, and not now that the World Cup is very soon," the 73-year-old said.
"No one was thinking that Brazil has three important events - the Confederations Cup, World Cup, and Olympics - to show off the country, to bring foreign exchange and tourism."
