Saudi Arabia has deposited $250 million (Dh918m) into the central bank of Sudan to support its financial position, the Saudi Finance Ministry said.
The grant is part of a package with the UAE worth $500 million announced in April. Both countries pledged an overall $3 billion in aid, with the rest going towards fuel, wheat and medicine.
The grant is aimed at alleviating pressure on the Sudanese pound and achieving stability in its exchange rate, the ministry said.
In December, mass protests began against president Omar Al Bashir because of the declining value of the currency and shortages of basic goods. In April, after months of demonstrations, the Sudanese army toppled Mr Al Bashir, who was then arrested.
But Sudan's economy is still haunted by Mr Al Bashir's legacy – the penalties imposed for his support of militant groups and for the offensive he launched to crush rebels in the western region of Darfur.
Because Sudan is still listed by the United States as a state sponsor of terrorism and has $1.3 billion of IMF arrears, it is unable to tap the international body or the World Bank for support. Sudanese banks have struggled to re-establish correspondent relationships with foreign banks.
Shortages and the cost of staples are still leading to protests. On Monday, four students were among six people shot dead at a rally in Al Obei sparked by shortages.
While the ruling military council is negotiating with protest leaders about a transition to civilian rule, countries including the United States are urging the two sides to come to an agreement quickly so that the new administration can begin to try to tackle many of the underlying issues that sparked the original protests.
UAE Minister Of State For Foreign Affairs Dr Anwar Gargash said the joint Emirati-Saudi package was needed because Sudan is a country in need of support "after 30 years of military, Muslim Brotherhood dictatorship".
He said the UAE would like to help this important Arab state through a peaceful transition, but the pace of change and how it would look was a purely Sudanese affair.
