Hazem al-Beblawi says a government, which may include Muslim Brotherhood figures, will be formed by Sunday.
Egypt's new leadership is facing increased difficulties in forming an interim government after it issued an arrest warrant for the leader of the Muslim Brotherhood movement backing ousted president Mohamed Morsi.
Egypt’s interim prime minister Hazem al-Beblawi has said a new government will be formed by Sunday, a week after the popular military coup toppling Morsi.
Beblawi said on Thursday he would not rule out posts for Morsi's Muslim Brotherhood in the new cabinet.
But the Brotherhood rejected the offer, demanding Morsi's reinstatement and calling for fresh rallies on Friday against what it called "a bloody military coup".
The Brotherhood, for its part, accused the army of "massacring" its supporters.
Morsi's overthrow after nationwide protests demanding his resignation has plunged
Beblawi, who was appointed by the military on Tuesday, said: "So far I haven't approached anyone,” adding that he wanted to decide on the best candidates before asking them to join the government.
Al Jazeera's Rawya Rageh, reporting from Cairo, said the new leadership was moving quickly on announcing a new cabinet because it was under pressure to transfer power from military to civilian rule.
But the country remained deeply divided, as the military-backed government continued to crack down on the Muslim Brotherhood, ordering on Wednesday the arrest of its leader Mohamed Badie and other senior figures in the movement.
the arrest of its leader Mohamed Badie
They are wanted on suspicion of inciting clashes near an army building on Monday which killed at least 51 people, mostly Morsi supporters,
judicial sources said. The army said soldiers came under attack by "terrorists" and armed protesters.
Egypt into violent turmoil.
US arms deal
The latest development came as US officials said Washington will go ahead with plans to deliver four F-16 fighter jets to Egypt in the coming weeks.
The US has neither welcomed the toppling of Morsi nor denounced it as a "coup".
A US decision to brand his overthrow a coup would, by US law, require Washington to halt aid to the Egyptian military.
The jets, which will likely be delivered in August, are part of the annual aid package, a US defence official told Reuters news agency on Wednesday.
Another eight F-16s, built by Lockheed Martin Corp, are due to be delivered in December, the official said on condition of anonymity.
"There is no current change in the plan to deliver F-16s to the Egyptian military," a second US official said.
The Egyptian army receives $1.3bn in annual US assistance. The country has been one of the world's largest recipients of US aid since it signed a 1979 peace treaty with Israel.
It was the first Arab country to buy F-16s, widely viewed as a symbol of political and security ties with Washington.
US Defence Secretary Chuck Hagel has spoken by phone with the head of Egypt's armed forces, General Abdel Fattah al-Sisi, eight times since July 2.
Sisi was the country’s defence minister until he led the coup against Morsi.