Egypt's President-elect Mohamed Morsi is to address the people on the country's "rebirth" at a rally at Cairo's Tahrir Square on Friday, before being sworn in Saturday at the Constitutional Court.
Morsi "is taking part in the march of a million Egyptians at Tahrir Square and across the country," the official news agency MENA cited his spokesman Yasser Ali as saying, adding that he would "make a speech to the great Egyptian people".
Ali said that in his speech, Morsi will speak about "efforts to launch his programme for the rebirth of Egypt".
The Muslim Brotherhood, from which Morsi stood down after winning the presidential election, has called for a huge demonstration on Friday in Tahrir Square under the slogan: "Day of the transfer of power."
The presidency announced late Thursday that Morsi would be sworn in Saturday before the Constitutional Court, after differences with the army over the transfer of power to the nation's first civilian president.
Morsi "will go at 11 am (0900 GMT) Saturday to the Constitutional Court to take the oath before the Court's general assembly", said a statement released by MENA.
The president will then go on to Cairo University to celebrate his investiture and make an inauguration speech to the nation, the statement added.
Media reports said Morsi was consulting a cross-section of Egyptian society before appointing a premier and a cabinet mostly made up of technocrats.
Traditionally the president takes the oath in parliament, but Egypt's top court has ordered the disbanding of the Islamist-dominated legislature.
The military subsequently assumed legislative powers and also formed a powerful national security council headed by the president but dominated by generals.
By agreeing to be sworn in by the Constitutional Court, Morsi is effectively acknowledging the court's decision to dissolve parliament.
Morsi was "working on reaching some compromises on various issues so that all the parties are able to work together," Ali has said.
Egypt's first civilian president, and the first elected since an uprising ousted president Hosni Mubarak last year, still has to contend with the Supreme Council of the Armed Forces.
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The SCAF, which took control after Mubarak resigned, will retain broad powers even after it formally transfers control to Morsi.
The military reserves the right to appoint a new constituent assembly should the one elected by parliament be disbanded by a court decision expected on September 1.
But the Brotherhood insists that only parliament can appoint the assembly.
Morsi has already met SCAF chief Field Marshal Hussein Tantawi, as well as a delegation from the Sunni body Al-Azhar, and another representing Egypt's Coptic church.
US Secretary of State Hillary Clinton congratulated Morsi on Wednesday and praised the SCAF for facilitating the election.
"We have heard some very positive statements so far," she said, noting Morsi's pledge to honour international obligations "which would, in our view, cover the peace treaty with Israel" signed in 1979.
"We expect President Morsi to demonstrate a commitment to inclusivity that is manifested by representatives of the women of Egypt, of the Coptic Christian community, of the secular, non-religious community and young people," she added.
Clinton said Egypt's military "deserves praise for facilitating a free, fair and credible election".
The Council of Europe Parliamentary Assembly, while welcoming Morsi's election, said it was worried about "real obstacles to democracy" in Egypt, notably security and stability challenges in a deeply polarised country.
These "constitute real obstacles to a slowly emerging democracy in a country which has virtually no democratic experience," it warned.
The International Monetary Fund has said it was ready to help Egypt tackle its "significant immediate economic challenges".
Since late last year the IMF has been discussing with the interim leadership a possible $3.2 billion loan to help Cairo bridge fiscal shortfalls while restructuring the economy and financial system.
In other developments, the foreign ministry summoned the UAE ambassador over comments made by Dubai police chief General Dahi Khalfan criticising the Brotherhood, saying it does not represent Islam.
He also said the Egyptian revolution was "carried out by the youth, and the Brothers have harvested the fruits".