Mourinho wants cover for when Cameroonian forward Samuel Eto'o flies out for next month's African Nations Cup and has named Palermo's Edinson Cavani, Lazio's Goran Pandev and Italy striker Luca Toni as possible targets.
Moratti is unwilling to finance any purchases for the Serie A champions, however.
"At the moment there is no chance of Pandev or Toni arriving," Moratti was quoted as saying by the ANSA news agency.
"We are fine as we are and we will try to keep going with the forces we have.
"Mourinho has asked for a new buy but he knows the efforts the club have made. At the moment we don't intend to make moves because these are very important operations and I don't think it's appropriate to undertake them."
Toni is looking for a club after falling out of favour at Bayern Munich, while Pandev is seeking to be released from his contract with Lazio after being frozen out following a transfer request in the close season.
Eto'o's departure will leave Mourinho with three forwards to choose from - Diego Milito, Mario Balotelli and David Suazo - as Austrian Marko Arnautovic does not seem to figure in his thinking.
Inter's chief executive Ernesto Paolillo was quoted by Italian media on Thursday as saying that Arnautovic would return to Dutch club Twente Enschede when his loan deal expired.
