Saudi Arabia on Friday pledged $100 million to reconstruct areas of northeastern Syria formerly held by the Islamic State group, in a move sharply criticised by President Bashar al-Assad's regime.
The kingdom said the 88-million-euro contribution would go towards a US-backed campaign to "stabilise" the one-time IS bastion and to help ensure the jihadists cannot re-emerge as a threat.
The government in Damascus slammed the contribution as "morally unacceptable", in a statement carried by the official SANA news agency.
A longtime foe of Riyadh, it accused Saudi Arabia's royal family of supporting "terrorism and those who contributed to the killing of the people of Syria and the destruction of its infrastructure."
IS declared a "caliphate" after seizing swathes of Iraq and Syria in 2014, but has since been ousted from most of that territory including its former de facto Syrian capital Raqa and a pocket of Damascus.
Saudi Arabia, the United States' most powerful Arab ally, is a member of the US-led Global Coalition to Defeat ISIS, another acronym for the jihadist group.
Riyadh's contribution aims to support "stabilisation projects" and "will play a critical role in the coalition's efforts to revitalise communities, such as Raqa, that have been devastated by ISIS terrorists," read a statement by the Saudi embassy in Washington.
It said the money would "save lives, help facilitate the return of displaced Syrians, and help ensure that IS cannot reemerge to threaten Syria, its neighbours, or plan attacks against the international community."
In April, reports emerged that the United States was looking to build an Arab force to replace its troops in northeastern Syria. The US government has not officially confirmed the reports.
Despite the defeat of IS in Syria and Iraq, between 20,000 and 30,000 of its fighters remain in the two countries, according to a United Nations report released Monday.