Cairo: The Custodian of the Two Holy Mosques King Salman of Saudi Arabia on Monday wrapped up a landmark five-day visit to Egypt marked by lavish praise and multi-billion-dollar investment deals in a clear sign of support for President Abdel Fattah al-Sisi's regime.

The 80-year-old monarch's visit came as Riyadh aims to shore up ties with Cairo as it engages in several conflicts in the Middle East and competes with Shiite Iran for regional supremacy.

The visit also highlights Saudi Arabia's firm support for Egypt's fight against the jihadist Islamic State group which has spearheaded a brutal insurgency in the Sinai Peninsula since the ouster of Islamist president Mohamed Morsi in 2013.

"The other mission that we should work on together is the fight against extremism and the fight against terrorism" King Salman said on Sunday in an address to the Egyptian parliament.

On Monday he was awarded an honorary doctorate from Cairo University.

He later flew to Turkey where he was met by President Recep Tayyip Erdogan.

Over the past five days King Salman and Sisi signed a slew of multi-billion-dollar investment deals that included a plan to build a bridge over the Red Sea connecting Saudi Arabia and Egypt.

Egypt also agreed to demarcate its maritime borders with Saudi Arabia by officially placing two islands in the Straits of Tiran in Saudi territory.

The agreement provoked an immediate backlash in Egypt with thousands of Twitter users accusing Sisi of selling the islands. The islands had historically been Saudi and were "leased" to Egypt in 1950.

Analysts said Salman's visit puts to rest months of reports in Saudi and Egyptian media of strained ties between the two countries over Cairo's unwillingness to participate fully in Saudi-led operations against Iran-backed Shiite Huthi rebels in Yemen.

Egypt had announced it would back Saudi Arabia with ground forces if needed but appears to have balked at sending troops for fear of becoming mired in the conflict.

"The two countries realise that common interests outweigh their practical differences" said Fawaz Gerges professor of Middle East politics at the London School of Economics and Political Science.

Following Salman's visit Egypt would now be expected to offer more vocal support for Saudi Arabia when it comes to Iran and Yemen he said.

"The Egyptians are basically going to convince the Saudis that they are in the same trench when it comes to the Saudis' existential fight with Iran and Saudi Arabia too seems to be very committed to Egyptian national security and the Sisi adminstration" said Gerges.

- Economic aid -

Since he ousted Morsi in 2013 Saudi Arabia has supported former army chief Sisi.

Riyadh viewed Morsi's Muslim Brotherhood movement with deep suspicion.

Saudi support for Cairo has helped Sisi tighten his grip on Egypt after he crushed not just the Brotherhood but also secular dissidents.

Hundreds of supporters of Morsi have been killed and tens of thousands jailed in a blistering police crackdown.

Hundreds more including Morsi himself have been sentenced to death or lengthy jail terms after often speedy trials that have been condemned by the United Nations and global rights groups.

Prior to Salman's visit Riyadh had already pumped billions of dollars in aid and investment into Egypt. It has helped prop up Egypt's economy whose tourism industry has been devastated by years of political turmoil and jihadist attacks.

"Although Saudi Arabia's support is important to confront Egypt's economic crisis what Egypt needs is more political stability and security to attract tourism and foreign direct investments" said Ibrahim El-Ghitany a researcher at Cairo-based Regional Centre for Strategic Studies.

Egypt's economy which is heavily dependent on tourism was dealt a body blow when IS downed a Russian airliner over the Sinai Peninsula on October 31.

All 224 people on board mostly Russian tourists were killed in the attack which IS said was carried out by stowing a bomb on the aircraft.

AFP