Egypt's Vice President Omar Suleiman incurred the wrath of protestors and opposition groups after he warned they had two options left - dialogue or a coup.
"We can't bear this for a long time," Suleiman said of the Tahrir protests. "There must be an end to this crisis as soon as possible."
Demonstrators called the sharply worded ultimatum a dangerous threat as thousands fill Cairo's Tahrir Square for the 16th day on Wednesday.
The growing crowd was energized by Monday's release of young Google executive Wael Ghonim, who helped organized some of the first protests.
"This is the revolution of the youth of the Internet and now the revolution of all Egyptians," an emotional Ghonim said in a television interview hours after being freed.
After 12 days in the custody of Egypt's security services, the young Google manager wasted no time rejoining the protest rallies.
"We will not abandon our demand, and that is the departure of the regime," Ghonim told the crowd.
"Wael Ghonim moved the feelings of every Egyptian, people of all ages cried as they watched him," Shorouk Sobhy, who took part in the protests for the first time on Tuesday, told the Egyptian publication Al-Masry Al-Youm.
On Tuesday, U.S. Vice President Joe Biden telephoned his Egyptian counterpart, urging a prompt and peaceful transition. However, Egypt's United Nations ambassador warned that change may not be immediate.
"This is the beginning of a process that is going to take place," said Maged Abdelaziz, Egyptian ambassador to the U.N.
Meanwhile, there have been reports from Egypt that police have been releasing criminals from prisons so they can intimidate the protestors. But ant-government demonstrators vowed they would not leave until President Hosni Mubarak steps down.