Sudan's and Saudi Arabia's navies have launched their first joint maritime military drill in the Red Sea.
The naval exercises, which involve two Saudi naval vessels and troops, will continue for several days, according to the commander of the navy base in Port Sudan, Admiral Magdi Omer.
The training will focus on anti-smuggling operations and "boosting security and stability", according to Sudan's military spokesman, Sawarmi Saad.
The drill will form a starting point for strengthening relations between Sudan and Saudi Arabia and follows the docking of Iranian warships at Port Sudan in October and December.
Saudi Arabia has a tense relationship with Iran although Saad described the Iranian port calls as part of normal military exchanges between the two states.
Israeli officials have expressed concern about arms smuggling through Sudan. The arrival of the Iranian warships coincided with an air raid on Khartoum's Al-Yarmook military factory, which was at the centre of specualtion that Iranian weapons were stored or manufactured there. Sudan accused Israel of the strike.
Sudan's links with Tehran have been met with suspicions in the Gulf. The Saudi pro-government al-Riyadh newspaper slammed Khartoum over the Iranian warship in an editorial entitled "The fall of masks between Iran and Sudan".
"[Sudan's President Omar al-] Bashir's government resorting to a state that is at odds with most Arab countries and has no logical justification," the newspaper said.
In November, Sudanese foreign minister Ali Karti publicly criticised his own government for allowing Iran's naval warships to dock in Port Sudan and warned of damage to relations with its Arab Gulf state neighbours.