The United States has urged Egypt's President Mohamed Morsi to lead efforts in order to build a national consensus. "We call on President Morsi, as the first democratically elected leader of Egypt, to lead the effort before, during and after the voting to continue to try to build a national consensus, because otherwise, we're just going to see a repeat of the kinds of tensions that we've seen over the last month," said US State Department Spokeswoman Victoria Nuland on Thursday. Nuland said "the secretary's also raised these concerns, as have others, that there are legitimate questions both about the process and about the substance. And so there has been a question about whether this is going to build consensus, and we call on the president to continue to try to build that consensus. The US called all political figures in Egypt to renounce violence during a referendum on a draft constitution, slated for December 15 and 22. "We call on Egyptians- Egypt's political leaders of all stripes to make clear to their supporters that violence of any kind during this polling is unacceptable, and we call on the Egyptian people to take all possible measures to avoid confrontation and violence," Nuland said. "I think we've been clear all along that as the democratically elected president of the country, he's got responsibilities to the Egyptian people, and he's got responsibilities to Egypt's future," Nuland added