Mubarak remains in power in Cairo, although he dismissed the members of his government and appointed a new vice prime minister and vice president, CNN reported.
"This is a country that is falling apart," ElBaradei said.
A national unity government is necessary to fill the void during Egypt's transition period from dictatorship to democracy, and it should hold "fair and free" elections, ElBaradei said.
"I think this is a hopeless, desperate attempt by Mubarak to stay in power. It is loud and clear from everybody in Egypt that Mubarak has to leave today, and it is non-negotiable for every Egyptian," ElBaradei said.
"Egypt needs to catch up with the rest of the world. We need to be free, democratic, and a society where people have the right to live in freedom and dignity," he said.
ElBaradei said if the Egyptians request he serve, he would be the interim president.