The president of football's controlling body FIFA, Joseph Blatter, said on Sunday that he still believed in South Africa as the 2010 World Cup host, the dpa reported.
But Blatter also revealed that FIFA had a plan B ready should worse come to worst.
Blatter told Austrian state broadcaster ORF that there were some concerns about infrastructure and security.
He expressed his belief the 2009 Confederations Cup in South Africa will be the ultimate test run and if that was not satisfactory, it would be time to look at alternatives.
"But at the moment an earthquake would have to occur to prevent the World Cup from being held in South Africa. However, I would be a negligent FIFA boss if there was no plan B in the cupboard," Blatter said.