Western states are expected to push for Syria to be referred to the UN Security Council after UN inspectors gave independent support to US allegations that Damascus was building a covert nuclear reactor, diplomats say.
In a report to member states on Tuesday, the International Atomic Energy Agency's chief assessed that a site in the Syrian desert bombed to rubble by Israel was "very likely" to have been a reactor that should have been declared to the IAEA.
Western diplomats said this meant that Syria had failed to meet its obligation to cooperate with the UN atomic watchdog – which seeks to ensure that nuclear technology is not diverted for military purposes and that no sensitive work is hidden.
They said their approach to the Syrian nuclear issue was not linked to Western condemnation of the Arab state's crackdown on pro-democracy unrest, stressing that Syria had stonewalled an IAEA probe for nearly three years and it was now time to act.
The United States and its European allies are expected to use the IAEA report's finding to lobby for a resolution by the agency's 35-nation board, meeting on June 6-10 in Vienna, to refer the Syrian file to the Security Council in New York.
"Such a move would send a strong signal that the international community will not tolerate egregious acts of nuclear proliferation," Paul Brannan of the Washington-based Institute for Science and International Security said.
A tough line may also add pressure on Iran, diplomats said. A second report by IAEA chief Yukiya Amano leaked on Tuesday said the agency had received new information about possible illicit military dimensions to Iran's nuclear activities.
Since mid-2008, Syria has refused to allow UN nuclear inspectors to revisit the site known as Dair Alzour, which US intelligence reports said was a nascent, North Korean-designed reactor intended to produce plutonium for atomic bombs.
Syria says it was a military, non-nuclear complex before Israeli warplanes wrecked it in 2007. But that assertion was rejected in the IAEA's latest report on Syria, which cited satellite imagery, Syrian procurement efforts and analysis of samples gathered at a one-off inspector visit in 2008.
"We now have a case of non-compliance when the director general has made his assessment that this was a secret nuclear reactor," one diplomat said, adding that Western states were already meeting to draft an IAEA board resolution on the issue.
Asked if the expectation was that the draft would include a referral clause, the diplomat said: "Yes." Another Western diplomat also made clear that was the aim, but that the final result would depend on wider consultations with board members.
The board has the power to refer countries to the Security Council if they are judged to have violated global non-proliferation rules by engaging in covert nuclear work.
It reported Iran to the Security Council in 2006 over its failure to dispel suspicions that it was trying to develop nuclear weapons. Tehran has since been hit with four rounds of UN sanctions over its refusal to curb sensitive nuclear work.
Syria, an ally of Iran, denies harboring a nuclear weapons program and says the IAEA should focus on Israel instead because of its undeclared nuclear arsenal.
Some non-Western members of the IAEA board have expressed doubt about taking strong action against Syria, saying that whatever happened at Dair Alzour was now history. The board debate may turn out to be "difficult," one envoy said.
Diplomats say it remains unclear whether Russia and China, which last month resisted a Security Council condemnation of Syria's clampdown on protests, would vote for a referral.
Pierre Goldschmidt, a former head of global inspections at the IAEA, said Syria must fully cooperate with the agency but that its case was different from that of Iran and he suggested this may make Damascus more ready to back down.
"Very few people would believe today that Syria after the September 2007 bombing still represents a nuclear threat in the foreseeable future," Goldschmidt said.
"I think that their nuclear development is at such an early stage that the threat of (Security Council) sanctions might persuade them to follow Libya's example."
Seeking to mend ties with the West, Libyan leader Muammar Qadhafi agreed in 2003 to abandon efforts to acquire nuclear, chemical and biological weapons.