Egyptian President Mohamed Morsi has refused to call off a disputed Constitutional referendum or curb the sweeping powers he granted himself in a decree last month, leaving opposition protesters even more infuriated with a President who they say is acting like a dictator.

Speaking on national television amid anti-government protests gripping Cairo, Mr. Morsi insisted that dialogue is the only solution to the country's constitutional crisis. He said he will not tolerate killings or sabotage. He said seven people were killed outside the presidential palace, with more than 700 others injured during demonstrations this week. The president said 80 people have been arrested for crimes, including the use of firearms.

U.S. President Barack Obama spoke with Mr. Morsi by telephone today to voice deep concern about the protest deaths and injuries. A White House statement said Mr. Obama also urged all Egyptian political leaders to make clear to their supporters that violence is unacceptable.

Mr. Morsi said he will form a new advisory panel to write a new draft constitution if voters on December 15 reject the one passed by his Islamist followers last week.