VIENNA - UN nuclear inspectors made no headway in talks in Syria last month to try and kick-start a long-stalled investigation into its atomic activity, IAEA chief Yukiya Amano said on Thursday.In an attempt to advance its investigation into possible military nuclear activities in the Arab state, the International Atomic Energy Agency (IAEA) took part in two days of discussions in the Syrian capital in October.RELATED:Tanks enter Deir al-Zor in east Syria, residents say 'Syria's nuclear plant linked to 3 other facilities' The IAEA has been seeking access to a desert site at Deir al-Zor, which US intelligence reports say was a nascent, North Korean-designed reactor intended to produce plutonium for atomic weaponry before Israel bombed it to rubble in 2007.The Vienna-based UN nuclear watchdog has also been seeking information about other sites that may have been linked to Deir al-Zor.Syria says Deir al-Zor was a non-nuclear military facility, but the IAEA concluded in May that it was "very likely" to have been a reactor that should have been declared to inspectors."Unfortunately, no progress was made in meetings with the Syrian authorities on obtaining the full access which we have requested to other locations which the agency believes are functionally related to the Deir al-Zor site," Amano said."I urge Syria to cooperate fully with the agency in connection with unresolved issues related to the Deir al-Zor site and other locations," he said in an address to the IAEA's 35-nation board of governors. In June, the board voted to report Syria to the UN Security Council, rebuking it for failing to cooperate with the agency's efforts to get concrete information on Deir al-Zor and other sites. Russia and China opposed the referral, highlighting divisions among the major powers.