SOWETO, South Africa (CNN) -- With 62 days to go before the football World Cup opens, FIFA - the sport's governing body - and the South African local organizing committee are pleading with South Africans to buy the remaining 500,000 tickets that have been made available.

The tickets are for 63 matches, excluding the final, and will go on sale April 15.

It has become clear that fewer than the 450,000 foreign visitors initially expected will be coming to Africa's first World Cup. A significant number of the tickets that have been made available come from FIFA and its affiliates that have decided not to use them.

"This final ticket phase is very important," said FIFA Secretary General Jerome Valcke at a press conference in Soweto. "We will not want to give that picture of empty seats to the world; all will need to be done in these last days."

Ticket sales have been hampered by factors ranging from location of the host country -- over 15 hours from New York by air, 11 hours from London and eight hours from Sao Paulo, Brazil -- to the global economy and its impact on leisure travel.

World Cup organizing head Danny Jordaan made an impassioned plea to his fellow South Africans to buy the remaining tickets.

"We have done everything we were asked to do. We have created a [reduced price] category of tickets exclusively for South Africa. We have now implemented over-the-counter sales to make sure the tickets are accessible," he said. "The final thing is that South Africans must respond. If you are a good host, you must be there."

So far tickets have been sold online and at a local bank. But the majority of South Africans do not have access to the Internet and the bank option has not been popular.

Local fans are used to buying tickets at the stadium -- hence the introduction of an over-the-counter option.