Updated

Egypt's Islamist president ordered his defense minister and chief of staff to retire on Sunday and canceled the military-declared constitutional amendments that gave top generals wide powers.

It was not immediately clear whether the decision had the military's blessing. Morsi has been in a power struggle with the military since he came to power on June 30. Shortly before he was announced the winner of elections, the ruling military council that took power after Hosni Mubarak's ouster stripped the presidency of many of its key powers.

Morsi also appointed a senior judge, Mahmoud Mekki, as vice president. All decisions are effective immediately.

Outgoing Defense Minister Hussein Tantawi headed the ruling military council for 17 months after Mubarak's ouster in February 2011. Before that, he was defense minister for nearly two decades under Mubarak. The military council's No. 2, Chief of Staff Sami Annan, was also ordered to retire. But both men were appointed advisers to Morsi, according to state television.

Presidential spokesman Yasser Ali said told a news conference aired on state TV that Morsi named a career army officer, Lt. Gen. Abdel-Fattah el-Sissi, to replace Tantawi and Lt. Gen. Sidki Sayed Ahmed to replace Annan.

Morsi also ordered the retirement of the commanders of the navy, air defense and air force. The retired navy commander, Lt. Gen. Mohan Mameesh, was named as chairman of the Suez Canal, the strategic waterway linking the Red Sea and the Mediterranean and a major source of revenues for the country.