Syria on Monday handed over the remaining 100 tonnes of toxic material it had declared to the global chemical weapons watchdog, but the country cannot be declared free of the weapons of mass destruction, the organisation's chief said, Reuters reported.
The chemicals, roughly 8 percent of a total 1,300 tonnes reported to the Organisation for the Prohibition of Chemical Weapons (OPCW), had been held at a storage site which the government of President Bashar al-Assad previously said was inaccessible due to fighting with rebels.
The security situation in the area has now improved and the containers of chemicals were taken by truck to the Syrian port of Latakia and loaded onto a ship to be destroyed at sea on a specially equipped U.S. vessel, said OPCW chief Ahmet Uzumcu.
"A major landmark in this mission has been reached today. The last of the remaining chemicals identified for removal from Syria were loaded this afternoon aboard the Danish ship Ark Futura," Uzumcu told a news conference in The Hague.
The bulk of Syria's chemical stockpile had already been shipped out of Latakia, part of a multi-million-dollar operation involving some 30 countries.
Syria agreed last September to destroy its entire chemical weapons programme under a deal negotiated with the United States and Russia after hundreds of people were killed in a sarin gas attack in the outskirts of the capital, Damascus.
The agreement averted U.S. military strikes in response to the worst chemical weapons attack in decades, which Washington and its European allies blamed on Assad's regime. Assad blames rebels battling to oust him for the chemical attack.
It will be several months before Syria's entire chemical weapons programme can be destroyed, Uzumcu said.
Uzumcu said an investigation into alleged use of chlorine in Syria's civil war and a review of the list of chemicals Syria has admitted possessing would continue. Western governments have raised questions over the list provided by the Assad government.
"All declared chemical weapons have left Syria (but) clearly we cannot say as the secretariat of the OPCW that Syria doesn't possess any chemical weapons any more," he added.
"While a major chapter in our endeavours closes today, OPCW's work in Syria will continue. We hope to conclude soon the clarification of certain aspects of the Syrian declaration and commence the destruction of certain structures that were used as chemical weapons production facilities," said Uzumcu.
The process of neutralising the chemicals will take up to 60 days, he said, meaning Syria will miss a June 30 deadline to completely eliminate its chemical weapons programme.
Speaking in Cyprus on Monday, Sigrid Kaag, head of the joint U.N. and OPCW team of experts overseeing the removal of the chemical materials, said work would start within three months on a process to destroy 12 production sites and tunnels inside Syria linked to the chemical weapons programme.
Under the initial agreement, Syria had until next Monday to hand over its entire chemical stockpile and destroy all production and storage facilities in the country. Syria has missed several deadlines set out in the agreement.
It will take up to two months to neutralize and process the highly-toxic agents - including mustard gas, sarin and other highly-poisonous precursors for chemical warfare - with special equipment on board the U.S. cargo ship Cape Ray. Assad's government said it wants the U.N.-OPCW mission led by Kaag to end once all chemicals have been shipped.
But Western governments want the mission to continue to investigate numerous ambiguities in Syria's chemical weapons declaration and several alleged chlorine gas attacks, which they also blame on Assad's forces.
Last week OPCW investigators said preliminary information supported the view of Western governments that chlorine-like chemicals not declared to the watchdog have been used in Syria. "We have to maintain pressure on Syria to ensure that the chemical weapons programme is completely and irreversibly dismantled, including remaining production facilities," said the European Union in a statement welcoming Monday's announcement.
"The EU urges all parties to help revive the political track as there can be no military solution to this conflict."
The civil war in Syria, now in its fourth year, has killed 150,000 people, displaced half the country's 22 million population and forced 2.8 million to flee.