President Mohammed Morsi of Egypt has warned that continuing unrest is "threatening to paralyse the country".
Troops have been deployed across Egyptian cities before the first anniversary of his taking office. The BBC reports weekend protests to demand his removal are planned.
Mr Morsi took power on 30 June 2012. His first year in office has been marred by constant political unrest and a sinking economy.
In a televised speech on Wednesday evening, the president said he had done "his best to evaluate the situation".
"I was right in some cases, and wrong in other cases," he said.
"I have discovered after a year in charge that for the revolution to achieve its goals it needs radical measures.
"Every revolution has enemies and every nation has challenges," Mr Morsi said, adding that he would "address the negatives".