Thousands of supporters of ousted Egyptian President Mohammed Morsi have defied a new warning from the military-backed cabinet and are continuing their sit-ins in the capital, Cairo.
The country’s interim leaders have ordered police to end ongoing protests at two sites in the city.
But Mr Morsi’s Muslim Brotherhood said they had no option but to continue the month-long sit-ins.
The United States has again urged Egypt to respect freedom of assembly.
Pro-Morsi demonstrators want to see the Islamist leader reinstated. He was removed by the army on 3 July, after just one year in office.
They have defied previous threats of removal, despite clashes with security forces that have left dozens dead.
The Egyptian interior ministry says gradual steps will be taken to disperse the crowds.
“The continuation of the dangerous situation in Rabaa al-Adawiya and Nahda squares, and consequent terrorism and road blockages, are no longer acceptable given the threat to national security,” it said in a statement on Wednesday.
Police had been tasked to end the demonstrations “within the law and the constitution”, it added.
‘Attempt to terrorise’
But Essam el-Erian, vice president of the Freedom and Justice Party, the Brotherhood’s political party, said the protesters would not be deterred by the latest threats.
“There are expectations of a massacre taking place in front of the eyes of the whole world,” he said.
“The free people in Egypt and the world must stand against this stupid cabinet mandate for the police to end the sit-in protests.”
The main protest sit-in is at a square near the Rabaa al-Adawiya mosque in the capital’s north-east, where clashes erupted on Saturday in which some 70 people were killed, and in Nahda Square near the main campus of Cairo University.
“Nothing will change,” Brotherhood spokesman Gehad el-Haddad told AFP news agency after the cabinet threat.
He dismissed the dispersal announcement as an “attempt to terrorise Egyptians” and said the decision to clear the camps had been taken by a “gang” that had no respect for the law.
Another Muslim Brotherhood member, Mohamed el-Beltagy, told Associated Press the army had forgotten “its main role in protecting the Egyptian borders and decided to kill its people”.
The government has not given details of when the clearance could happen.
US state department spokeswoman Marie Harf appealed for it to avoid violence.
“We have continued to urge the interim government officials and security forces to respect the right of peaceful assembly,” she said.
“That obviously includes sit-ins. So we’ve made that point publicly and privately, and we’ll continue to do so.”
Meanwhile, three top Muslim Brotherhood figures have been referred to court on charges of inciting violence.
Brotherhood leader Mohammed Badie, his deputy Khairat al-Shater and senior leader Rashad Bayoum face trial over allegations of inciting the killing of protesters outside of their headquarters last month.
An African Union delegation confirmed on Wednesday that it had met Mr Morsi, who has not been seen in public since being ousted.
He had received no official visitors until Tuesday, when he met EU foreign policy chief Catherine Ashton who said he was “well”.
The ousted leader has been formally remanded in custody at an undisclosed location, according to a judicial order.
He has been accused of the “premeditated murder of some prisoners, officers and soldiers” when he and several Muslim Brotherhood leaders were freed during a breakout at a Cairo prison in January 2011.
He is alleged to have plotted attacks on jails in the uprising that overthrew President Hosni Mubarak.
Mr Morsi is also accused of conspiring with the Palestinian militant group Hamas, which governs the Gaza Strip and has strong links with the Muslim Brotherhood.
He was overthrown by the military after mass rallies in which millions of Egyptians calling for his removal took to the streets.