Mansour, who was sworn into office on Thursday, met with army chief and Defence Minister General Abdel-Fattah el-Sissi as well as Interior Minister Mohammed Ibrahim, who is in charge of the police, at the Ittihadiya presidential palace.
He also met with his new aides -- constitutional consultant Judge Aly Awad Saleh, political consultant Mustafa Hegazy, and security consultant General Rafaat Shehata.
The source said that Adly focused his discussion with constitutional and political aides on a new constitutional declaration that will be announced soon. The declaration will provide details on how the upcoming transitional period will be managed.
Adly will also meet with representatives of different political forces and members of the Rebel movement.
More From This Section
Meanwhile, a tense calm has descended on Egypt following a night of fierce clashes between supporters and opponents of Morsi.
Tens of thousands of angry supporters of 61-year-old ousted president, chanting slogans like "down with military rule", took to the streets after Friday prayers demanding his reinstatement.
In the capital, the protesters holding images of Morsi marched towards the Republican Guards Club, where Morsi is believed to have been put "under guard" since Wednesday night.
Despite warning from soldiers, the crowd tried to storm the Guards headquarters, prompting the soldiers to open fire - first into the air, then at the demonstrators, killing four demonstrators and wounding dozens, local media reported.
In running street battles in Cairo, more people were dead, including two at iconic Tahrir Sqaure, and scores of others injured, reports said.
Meanwhile, Brotherhood-led National Alliance in Support of Electoral Legitimacy today vowed more protests in support of the deposed president.