Assessing the potential nuclear dangers of U.S. military intervention in Syria could place the International Atomic Energy Agency in violation of its mandate, Washington's envoy to the U.N. nuclear watchdog said on Monday.

The Vienna, Austria-based organization "must determine whether there is a scientific basis for conducting a highly speculative investigation of this kind," Ambassador Joseph Macmanus in a statement prepared for delivery at a meeting of the 35-nation IAEA Board of Governors.

The warning followed a Russian call for the agency to consider how a possible attack on its Damascus ally might create new threats involving locally stored atomic substances.

Moscow's push for the analysis brings up a range of concerns tied to statutes, politics and implementation, IAEA Director General Yukiya Amano said to reporters on Monday. "I hope people understand that [responding] takes time," he added, noting that Moscow had pushed for a quick answer from his agency.

An attack would risk dispersing highly enriched uranium to the surrounding environment, Russia has warned. The bomb-usable material could not be tracked following an aerial assault, Moscow indicated, possibly alluding to the material's vulnerability to seizure by nonstate actors.

Amano said Syria's only known research reactor does not contain a "big amount" of highly enriched uranium, but he added that additional radiological materials could be in storage at multiple Syrian medical and scientific facilities.

Former IAEA safeguards chief Olli Heinonen said the Middle Eastern country "should have substantial amounts" of atomic assets such as radioactive cobalt isotopes.

Such holdings could be "of a greater concern, if they end up in wrong hands," Heinonen told Reuters by e-mail. "Normally they are stored in protected vaults."http://www.nti.org/gsn/article/us-warns-iaea-over-assessing-nuclear...