The International Atomic Energy Agency (IAEA) is preparing to remove nuclear material from a clandestine site in Syria linked to the country’s former nuclear programme, following a US-brokered diplomatic agreement involving Syria and Israel.
Syria’s Atomic Energy Commission said on Tuesday (August 12) that an IAEA delegation would visit the country and announce “significant progress.”
The agreement concerns a secret facility known as “Site 99,” where material connected to the nuclear programme of former Syrian President Bashar al-Assad’s government was reportedly stored.
According to an Axios report citing Israeli and US officials, the Trump administration and the IAEA worked with Syria and Israel to find a diplomatic solution after Israel raised concerns about the material remaining at the site.
What is Site 99?
Site 99 is one of several Syrian locations associated with the Assad government’s clandestine nuclear programme.
The programme was centred on the Al-Kibar reactor, a facility near Dair al-Zour that Israel destroyed in an airstrike in 2007. The IAEA subsequently assessed that the destroyed facility was very likely a nuclear reactor that Syria should have declared under its safeguards obligations.
Although much of Syria’s suspected nuclear infrastructure was destroyed, other research, storage and related facilities remained.
Israeli officials told Axios that Assad’s government had stored nuclear material from the Al-Kibar project at Site 99.
A US official according to the news outlet said the material included yellowcake, a uranium-ore concentrate that can be processed further as part of the nuclear fuel cycle. Other residue and material left over from the Al-Kibar project was also reportedly stored there.
Why was Israel concerned?
Israel has been monitoring Site 99 for more than two years, according to Israeli officials.
The concern intensified after the fall of the Assad government in December 2024. Israeli officials feared that Syria’s new authorities could gain access to the material.
Israel reportedly told the Trump administration that it would not accept the nuclear material remaining unsecured at the site. Israeli officials even raised the possibility of a strike if the material was accessed or attempts were made to move it.
Instead, Washington pushed for an agreement under which the Syrian government would cooperate with the IAEA to secure and remove the material.
Fears over Syria accessing nuclear material
The situation as per the media outlet became more urgent several weeks ago when Israeli surveillance detected movements around Site 99.
Israeli and US officials reportedly feared that Syria’s new government might be attempting to access the material. Israeli officials were also concerned that Turkey could be helping Syria gain access.
The Trump administration asked Israel not to take military action and brought the IAEA into the discussions.
The resulting agreement between the IAEA and the Syrian government was signed about three weeks ago, according to the Axios report.
The material, however, has not yet been removed.
Could the material be used for a nuclear weapon?
The material at Site 99 is not believed to be capable of being directly used to make a nuclear weapon.
However, the radioactive material could potentially be used in a “dirty bomb” — a conventional explosive designed to spread radioactive contamination rather than produce a nuclear explosion.
That possibility added urgency to efforts to secure the site.
Israeli forces reportedly bombed entrances to the facility shortly after Assad’s government collapsed, with the aim of preventing unauthorised access.
Syria’s nuclear past
The Assad regime’s alleged nuclear activities have been a longstanding concern for the IAEA.
The agency has repeatedly said it was very likely that the facility destroyed at Dair al-Zour in 2007 was an undeclared nuclear reactor. Syria’s cooperation with the IAEA was limited for years.
Following the fall of Assad, however, Syria’s new authorities agreed to greater cooperation with the nuclear watchdog.
In 2025, the IAEA said the new Syrian government had agreed to cooperate fully and transparently in addressing questions surrounding the country’s past nuclear activities. The agency subsequently carried out visits and collected environmental samples at locations linked to the former programme.
US diplomatic push
The Site 99 episode has also become an example of Washington’s evolving relationship with Syria’s post-Assad government.
US officials told Axios that the Trump administration’s close relationship with the new Syrian authorities helped prevent the nuclear-material dispute from escalating into a wider regional crisis.
The episode involved sensitive coordination between Washington, Jerusalem, Damascus and the IAEA, with officials seeking to avoid a situation that could have drawn Turkey into the dispute.
