UN chief Ban Ki-moon called on the international community Friday to sanction those responsible for Syrian chemical weapons attacks documented in a newly released report.

The UN report, issued Thursday, concluded that such banned arms were used at least five times before Damascus agreed to dismantle its arsenal.

"I deplore in the strongest possible terms the use of chemical weapons in Syria, which is an offense against the universal values of humankind," Ban told the United Nations General Assembly.

The report did not, however, lay blame for the attacks, as the inspectors' mandate did not allow them to designate a responsible party.

"The international community has a moral and political responsibility to hold accountable those responsible to deter further incidents and ensure that chemical weapons can never reemerge as an instrument of warfare," Ban said.

The UN secretary general said he was "encouraged" by progress made in dismantling Syria's chemical arsenal.

"The international community continues to expect the Syrian Arab Republic will implement faithfully its obligations to complete the elimination by the first half of 2014," he said.

Under an international agreement brokered to avoid US military strikes on the Damascus regime -- which resulted in a landmark Security Council resolution -- Syria's most dangerous chemical weapons have to be out of the country by a December 31 deadline and destroyed by June 30, 2014.

Swedish expert Ake Sellstrom, who led the UN investigation team that compiled the report, reminded reporters that the mandate did not allow him to point any fingers.

"These facts could be used by others who have the mandate ... I don't have information that could stand in court," he said.

Attributing the attacks "requires more efforts and resources" such as those of forensic investigators, Sellstrom said.

Western and Arab governments, human rights groups and Syrian rebels accuse the regime of carrying out the attacks. Syrian President Bashar al-Assad and his allies in Moscow and Tehran blame the rebels.

Angela Kane, UN high representative for disarmament affairs, said that "it is up to members states to open up a new chapter on accountability."

Samples collected by the investigators, she added, have been stored and are the property of the United Nations.

Ban also called on the six states that have not signed or ratified the Chemical Weapons Convention -- which outlaws the production, stockpiling, and use of chemical weapons -- to do so.