"Any direct intervention by the Egyptian state has now gained international legitimacy," said El-Sisi, who inspected military units on Saturday at an airbase near the border with Libya.
The Egyptian President said his country has the right to defend itself after receiving "direct threats" from "terrorist militias and mercenaries" supported by foreign countries.
The Egyptian head of state, in a speech addressed to the military of the base he visited, asked that they be prepared "to carry out any mission, here within our borders, or if necessary, outside our borders."
He pointed out that the objectives of an eventual intervention would be to protect Egypt's 1,200-kilometer western border, collaborate in achieving a ceasefire and restore stability and peace in Libya.
Libya is experiencing a social and economic crisis since the overthrow of President Muammar Gaddafi through the intervention of the North Atlantic Treaty Organization (NATO) in 2011.
"Our heroic forces are determined to complete the journey and liberate the entire region from terrorist militias (referring to Haftar's LNA), its mercenaries and its supporters," he said.