President Barak Obama has welcomed President Mohamed Morsi's calls for dialogue with opposition figures.
During a speech to the nation on Thursday, President Morsi invited all political forces for talks to put an end to the ongoing dispute over his 22 November constitutional declaration and the draft constitution. He said the constitution would be put to a referendum on 15 December as planned.
A White House statement on Thursday said Obama had urged Egyptian opposition leaders to take part in talks with the president without setting pre-conditions.
He stressed that all politicians in Egypt should tell their supporters that violence is not acceptable.
The US president reiterated his support for the Egyptian people and their transition to democracy.
The White House statement was issued after Obama had spoken with Morsi by telephone. The US president expressed deep concern about the deaths of and injuries sustained by protesters during recent clashes between pro- and anti-Morsi supporters at the presidential palace in Cairo.
President Obama said it was essential for Egyptian leaders to agree on a way forward.
The National Salvation Front, a recently created umbrella group comprised of liberal and leftist groups, had earlier issued a statement stating that the "authority" had lost its legitimacy and called for mass protests on Friday.
The front also rejected calls for dialogue after Wednesday's events.
The clashes outside the presidential palace have resulted in at least six dead and around 700 injured. Videos circulating on the internet have shown bearded men severely beating civilians.