CAIRO - Egypt and Saudi Arabia signed a pact in Cairo Thursday aimed at boosting military and economic ties between the two Arab allies.

Relations have warmed since the 2013 ouster of Islamist president Mohamed Morsi, with Saudi Arabia offering billions in aid to Egypt and Cairo participating in a Saudi-led bombing campaign against Iran-backed rebels in Yemen.

On Thursday, a Saudi delegation led by Deputy Crown Prince Mohammed bin Salman visited Cairo and signed the “Cairo Declaration,” also attending a military parade with President Abdel Fattah al-Sisi.

“The two sides stressed the need to exert all efforts to boost security and stability in the region, and to work together to protect Arab national security,” Sisi’s office said after the signing. Riyadh has emerged as a key supporter of Sisi since the then army chief ousted Morsi two years ago, offering $4 billion (3.7 billion euros) to help kick-start an economy battered by years of political turmoil. And Egypt has backed Riyadh’s air campaign against rebels in Yemen, regularly saying it shares a common vision with Riyadh on tackling the crisis there.

Cairo had previously said it would also be prepared to commit ground troops if required.

The new Cairo-Riyadh pact also backs building a new joint Arab military force to fight terrorism in the region. On August 27, Arab defence and foreign ministers are to gather in Cairo to discuss the modalities of the force.

Sisi has strongly advocated such a force to fight jihadists in the region after the Islamic State group claimed in February the beheading in Libya of 21 Coptic Christians, all but one of them Egyptian.

Meanwhile, the United States began Thursday delivery of eight F-16 fighter jets to Egypt, according to its embassy in Cairo, the first since Washington fully lifted in March a freeze on arms delivery.

The operation comes as Secretary of State John Kerry’s prepares to visit Cairo for a “strategic dialogue” Sunday amid a warming in ties that were strained after the army ousted president Mohamed Morsi in 2013.

Following the overthrow of Morsi, Egypt’s first freely elected leader, Washington froze $1.3 billion (1.2 billion euros) in annual military aid to Egypt.

It fully resumed assistance in March, and Cairo took delivery of two US fast missile boats last month. Washington had already delivered 10 Apache helicopters in December. The eight F-16 Block 52 jets “are being flown in directly from the United States, and will be immediately integrated into the Egyptian air force, joining its existing fleet of F-16 aircraft,” the embassy said.

All eight from this first batch will arrive by Friday, with four more to be delivered later this year.

“The F-16s provide a valuable capability that is needed during these times of regional instability,” the statement quoted senior embassy defence official Major General Charles Hooper as saying.

“Extremists threaten regional security and these weapon systems provide a new tool to help Egypt fight terrorism.”

In addition, the United States will continue providing follow-on support, maintenance and training for Egyptian pilots and ground crews.

Egypt has been battling jihadists in the Sinai Peninsula, who have pledged allegiance to the Islamic State group, and Washington has backed its efforts.

It has also voiced growing concern about the jihadist presence in its western neighbour Libya, where IS has exploited a power struggle between rival governments to expand its presence.

In February, Egyptian air strikes targeted IS positions in Libya after the group posted a video showing the beheading of 21 Coptic Christians, all but one of them Egyptians.

No details have been made available on Sunday’s talks, which will be co-chaired by Kerry and Egyptian Foreign Minister Sameh Shoukry.

Despite lifting its freeze on military aid, Washington has kept up public condemnation of the repression by President Abdel Fattah al-Sisi against Morsi’s supporters.

A police crackdown has left hundreds of Morsi supporters dead in street clashes, thousands more have been jailed and many sentenced to death in hasty trials.