The ruling Supreme Council of the Armed Forces gave Prime Minister Kamal Ganzouri presidential authority in the country, save the powers related to military and judicial affairs.
A source in the military told Egyptian news agency al-Ahram that Ganzouri's powers were "only temporary." The Egyptian Parliament would enjoy traditional legislative powers once the full assembly starts functioning, the source added.
Egyptians last week had elections for seats on the country's lower house of Parliament. Islamists with the Muslim Brotherhood's Freedom and Justice Party and the conservative al-Nour party dominated the polls, the first since President Hosni Mubarak was ousted in a popular uprising early this year.
Ganzouri this week ushered in his new Cabinet, which includes two officials left over from the Mubarak era.
Elections last week were preceded by protests over the pace at which SCAF was handing authority over to civilian leaders. Washington said it was accepting of a political landscape in Egypt dominated by Islamic groups like the Muslim Brotherhood so long as they upheld the spirit of democracy.
FJP Secretary-General Saad el-Kataany said his party would honor its leadership obligations but stressed the new Parliament reserves the right to make revisions.