Efforts by Western and Arab diplomats to mediate an end to Egypt's political deadlock between the interim government and Islamists have failed, the presidency said on Wednesday.
The statement suggested the government may now move against sit-ins by the Islamist supporters of ousted president Mohamed Morsi, which the international community fears could lead to further bloodshed.
"The phase of diplomatic efforts has ended today," the presidency said, referring to mediation by US Deputy Secretary of State William Burns and EU envoy Bernardino Leon, among other diplomats who travelled to Cairo.
"These efforts have not achieved the hoped for results," the statement added.
The presidency "holds the Muslim Brotherhood completely responsible for the failure of these efforts, and for consequent events and developments relating to violations of the law and endangering public safety."