Morsi decreed that all decisions made by him since assuming the presidency in June are not subject to legal challenges.
The president also granted immunity to the new constitutional assembly which is drafting Egypt’s new constitution and to the upper chamber of parliament, the Associated Press reports.
Morsi’s moves to augment his control come a day after he was praised by the Obama administration for his role in helping broker a ceasefire between Israel and Hamas.
But the newly-assumed powers for Egypt’s president are likely to raise concerns in the White House and in Congress among lawmakers already suspicious of the Islamist president.
Morsi faced criticism after he failed to quickly condemn protesters who scaled the walls of the U.S. Embassy in Cairo on Sept. 11. After the incident, lawmakers moved to block a State Department request for $450 million in financial aid to Cairo, a sum which is still in limbo.
The White House, though, saw the recent conflict in Gaza as a test for Morsi to play a more constructive role.
Morsi’s Muslim Brotherhood party is an ideological ally of Hamas, which rules in Gaza and is considered a terrorist group by the U.S. Israeli security officials argue the rockets hitting Israel’s cities were trucked through Egypt and smuggled through border tunnels into Gaza.
Israel last week launched air strikes on Hamas targets in Gaza in hopes of preventing further rocket attacks on their civilians.
Secretary of State Hillary Clinton, who traveled to the region to broker a ceasefire, met with Morsi on Wednesday, and shortly after announced the truce between Israel and Hamas.
The State Department said Clinton and Morsi had discussed ways that “Egypt and the US could work together to support the next steps” in the peace process.
President Obama had also been in close contact with his Egyptian counterpart, calling Morsi three times as both sides worked over the week to hammer out the ceasefire proposal.
Morsi’s new powers, though, are likely to receive criticism from Washington.
Egypt receives $2 billion in annual American aid and on Sunday Sen. Lindsey Graham on NBC’s Meet the Press warned Egyptian officials to “watch what you do and how you do it.”
“You’re teetering with the Congress on having your aid cut off if you keep inciting violence between the Israelis and the Palestinians,” Graham had said of the Gaza fight.