Riyadh is looking to strengthen its security ties against the backdrop of war between the United States and Iran, which has drawn in surrounding nations and disrupted shipping through the Strait of Hormuz and Red Sea.The war has emboldened Iran and its Houthi allies in Yemen, both of which have attacked Saudi Arabia, while analysts say Washington is now seen as an increasingly unreliable partner.Since the onset of the war, Saudi Arabia has grown closer to Turkey, Egypt and Pakistan, which have been pushing for mediation and a resolution to the conflict.The deal also comes as a truce between Riyadh and the Houthi rebels in neighbouring Yemen has broken down, with the Houthis launching attacks on Saudi soil and declaring a maritime blockade against Saudi Arabia, which they have attempted to enforce by attacking Saudi tankers.A source close to the Saudi military and government told AFP that although the deal between Riyadh, Ankara and Islamabad had been under discussion for a long time, "the latest developments in the region expedite it".A second source close to Saudi officials confirmed on condition of anonymity that the agreement would be signed on Friday.Turkish President Recep Tayyip Erdogan arrived in the Red Sea city of Jeddah on Friday, Saudi media reported, where he is due to meet Saudi Crown Prince Mohammed bin Salman and Pakistani Prime Minister Shehbaz Sharif.Sharif and Pakistan's army chief Asim Munir have also arrived in the kingdom, with Islamabad's information ministry saying on Friday they performed a pilgrimage to Mecca."Although taking place against the backdrop of heightened tensions in the Gulf, the visit will carry significance beyond the immediate crisis and short-term considerations," Pakistani foreign ministry spokesman Tahir Andrabi said on Thursday.Renewed Houthi attacks