Egyptian President Abdel-Fattah El-Sisi received a phone call from Saudi Arabia's King Salman Bin Abdel Aziz late Friday to discuss regional cooperation.
The call came following the visit of Deputy Crown Prince Mohamed Bin Salman to Cairo Thursday, where the two countries signed a new understanding dubbed the "Cairo Declaration."
"Both leaders underlined the essence of implementing the Cairo Declaration, which aims at combatting common regional threats," Egyptian presidency spokesperson Alaa Youssef said in a statement Friday.
The "Cairo Declaration" outlines six facets of cooperation; notably, the development of military cooperation and working towards establishing a proposed Joint Arab Force; enhancing joint cooperation and investment between the two countries in the fields of energy, electricity, and transportation; and defining maritime borders between the two countries.
Maritime borders between Egypt and Saudi Arabia have never been formally defined. The Red Sea, which separates the two countries, is the water body that is to be demarcated.
In May, Arab army chiefs-of-staff met and agreed to form a joint Arab military force, as proposed during the annual Arab League summit in March. The force is intended to combat common challenges, in particular terrorist organisations.
The oil-rich Saudi kingdom has been a strong ally, economically and politically, to Egypt since the ouster of Islamist president Mohamed Morsi in July 2013. It has donated many billions of dollars in support of the Egyptian economy since late 2013.