The comments today by Bassam Al-Sabbagh, Syria's envoy to the International Atomic Energy Agency, follow a similar request by Moscow in a meeting yesterday of the IAEA's 35-nation board.
Russia is Syria's strongest ally in efforts to prevent US air strikes on Syrian government targets in retaliation for a chemical weapons attack that killed hundreds of Syrians.
Al-Sabbagh expressed "deep concern" about the nuclear risks of an attack. He told reporters Syria feels the agency has the authority to do an assessment.
IAEA chief Yukiya Amano says he needs time to consider the request.