CAIRO — Since King Salman of Saudi Arabia arrived in Cairo on Thursday for a five-day visit, the leader of the oil-rich kingdom has lavished his Egyptian allies with promises of aid and investment.

But this time, instead of writing a blank check with little more than a polite “thank you” to show for it, King Salman will return home Monday with something more substantial in return: two islands in a strategic corner of the Red Sea.

Egypt’s cabinet announced on Saturday that it was transferring sovereignty of Tiran and Sanafir, arid and uninhabited islands at the mouth of the Gulf of Aqaba, to Saudi Arabia. The cabinet tried to suggest that the transfer, pending approval from Parliament, merely returned Saudi Arabia’s own territory.

Saudi Arabia transferred Tiran and Sanafir to Egyptian control in 1950 amid concerns that Israel might seize them.