BRUSSELS (Reuters) - No date has been set for the beginning of formal talks on a new rescue program for Greece because international creditors are still looking for a secure place to hold negotiations in Athens, a European Commission official said on Friday.

Greek government officials have said repeatedly that the talks on a bailout of up to 86 billion euros ($94 billion) would start in Athens on Friday.

But representatives of Greece's creditors -- the European Commission, the European Central Bank and the International Monetary Fund -- say they cannot start until the right location is found, given the sensitivity of the talks and the fact that many Greeks detest the lenders after two painful bailouts.

"There are some logistical issues to solve, notably security-wise," a European Commission official said. "Several options are on the table," the Commission official said, without giving more details.

At the moment only technical talks are underway to sort out logistical issues, several officials said.

A deal on a new bailout program needs to be reached by Aug. 20 when Greece is due to pay 3.4 billion euros to the ECB.

(Reporting by Francesco Guarascio in Brussels and Ingrid Melander in Athens, editing by Robin Emmott)