"The first priority is to impose security, counter-terrorism firmly and legally, and restore stability by preserving human rights and democracy," he said in the televised address.
Mahlab had a message for working Egyptians as well, al-Bawaba, an online news website based in Amman, Jordan, reported.
"I urge you to end any sit-ins, strikes and protests. Let's begin rebuilding the nation," he said.
The recent resignation of the Egyptian government prompted a shakeup in the governmental structure, and Mahlab's appointment of a 31-member cabinet. National elections are planned for the spring.