A budget shortfall and low ticket sales for next month's Paralympics in Rio will mean fewer venues and staff, the president of the International Paralympic Committee (IPC) says.
Sir Philip Craven said the level of support expected from the organisers in Rio had been lower than promised, but the Games would go ahead, and he hoped people would still want to go to the events.
"We now hope a new promotional campaign will engage the Brazilian public and lead to strong crowds for all sports.
"At this point it is difficult for us to expect the full venues we saw in Beijing or London, or expect to see in Tokyo in four years' time."
The IPC said Rio's organising committee had not raised enough money to fund the Paralympics, which start on 7 September, and so far only 12 percent of tickets have been sold.
Cuts will be made to venues, the workforce and transport.
Sir Philip said nothing like the current circumstances had ever occurred before in the 56-year history of the Paralympics.
The organisers were also meant to pay travel grants to all 165 participating countries by the end of July, but the first instalments were only now being paid.
However, Rio's mayor, Eduardo Paes, has secured millions of dollars in additional funding and sponsorship from state-run companies after the lifting of an injunction that had blocked further state aid for the Games.
Despite the problems, Sir Philip said the Games would "act as a catalyst to positive social change in Brazil and Latin America".
He added: "We are working desperately hard to protect athlete services, especially within the field of play.
"They have dedicated their lives to reaching these Games and we will do our utmost to try to maintain the service levels and scope that they expect at a Paralympic Games."