At a closed door meeting, Western governments led by the United States took Syria to task for failing to surrender its chemical weapons under ambitious deadlines agreed with Russia after a poison gas attack in August.

Speaker after speaker stood up to berate Damascus at the Organization for the Prohibition of Chemical Weapons (OPCW), until it came to Russia's turn and Moscow took a much more lenient view - the international split over Syria writ large.

Russia defended President Bashar al-Assad and said his government needed more time to ship the chemicals safely through territory where it is fighting rebels.

Syria missed a first deadline to give up the most dangerous toxins on December 31 and another cut-off date passed on Wednesday, when it was due to hand over all the remaining critical chemical materials.

The success of the destruction program, now also at risk of missing the final June 30 deadline, is in the interests of both powers, but the confrontation in The Hague on January 30 exposed a deep division between Moscow and Washington over how to respond to Syria's lack of progress.

The US-Russian clash also bodes poorly for a broader Moscow-Washington partnership that is seen as critical to resolving other major foreign policy challenges, from Iran's nuclear program to the Geneva peace talks for Syria, which are set to resume on Monday. Further bad feeling was aroused by a leaked phone conversation about Ukraine between US officials.

Even with the latest setback, the agreement to destroy Syria's chemical stockpile that averted a US-led military strike and led to a Nobel Peace Prize for the OPCW, can still be pulled off, UN Secretary General Ban Ki-moon has said.

The next major deadline is March 31, by when the most toxic substances are supposed to be destroyed outside Syria on a special US cargo vessel, the Cape Ray, which is on the way from Virginia.

"The odds of Syrian compliance increase if Washington and Moscow speak with one voice, but that isn't happening at present," Amy Smithson, a chemical weapons expert at the US Monterey Institute, a leading think tank, told Reuters.

"These two countries are both key to the potential success of chemical disarmament in Syria, not to mention a settlement to the overall conflict, so hopefully they will rapidly find a way to resolve this impasse," she said.

With Russia opposed to automatic UN Security Council action against Syria if it is deemed non-compliant - a stage diplomats say has not been reached - Washington finds itself in a similar situation to last September, when it had threatened military action, diplomats said.

Western powers fear the program is being stalled intentionally to give Moscow more time to provide military hardware to Damascus and to enable Syria to retain its weapons of mass destruction as a negotiation tool in the Geneva peace talks.

It is a process that has faced difficulties from the beginning, with OPCW inspectors held up in Cyprus for weeks before they could get into Syria to check its chemical arsenal. The August 21 gas attack happened within days of their arrival and inspectors were earlier shot at by snipers while trying to check allegations of chemical weapons use.

Even as Moscow supports Assad in public, it is being urged to put pressure on him to meet the targets. On Tuesday Russian Deputy Foreign Minister Gennady Gatilov said Syria was planning a large shipment of chemical substances this month and was ready to complete the process by March 1.

Still Western diplomats complained that the Russians were not doing enough to encourage Assad to play ball, while other powers may be reluctant to threaten action for fear of undermining the Geneva talks.

"There are signs that the Russians are putting pressure on them (Syria) to do it," a Western diplomat said. If the Syrians complete the shipments of toxic chemicals by March 1, as the Russians said then "that would be good."

Washington and other Western governments have rejected Syria's claim that it needs more equipment to transport chemicals securely after it received a long list of hardware to carry out the job.

The delay is already having a knock-on effect on the complex logistical task, involving nearly a dozen countries, commercial chemical destruction contracts and multi-million dollar funding by the international community.

The international community has invested heavily in the operation, providing ships, vehicles, personnel and tens of millions of dollars in donations to OPCW and UN funds.

Washington sent shipping containers, GPS trackers, armored vehicles for inspectors, decontamination equipment and a cargo ship outfitted with $10 million in chemical weapons treatment systems.

China chipped in ambulances and surveillance cameras, Belarus gave 13 field kitchens, Russia sent 75 transport vehicles, 25 of them armored. Denmark and Norway donated cargo ships and military patrol boats. Italy offered use of a port. Germany and Britain will make available toxic waste destruction facilities.

"While remaining aware of the challenging security situation inside Syria, it is the assessment of the Joint Mission that the country has sufficient material and equipment to carry out multiple ground movements to ensure the expeditious removal of chemical weapons material," Ban said last week.

A senior Western diplomat said the Syrian government is "teasing us" by dragging its heels while doing enough to avoid being declared in non-compliance with its obligation to destroy its chemical weapons program.

"Our impression is that they (Assad's government) are managing this issue in parallel with the Geneva discussion," he said. "Everything is blocked so they are blocking on the chemical weapons to remind us" of their power on this issue.

That sentiment was echoed by the US Ambassador to the OPCW, Robert Mikulak, who called on Damascus at the closed OPCW meeting to "take immediate action" to resolve the impasse.

"Syria has said that its delay in transporting these chemicals has been caused by 'security concerns' and insisted on additional equipment - armored jackets for shipping containers, electronic countermeasures, and detectors for improvised explosive devices. These demands are without merit, and display a 'bargaining mentality' rather than a security mentality," he said.

On February 6, a day after the deadline to hand over all critical chemicals expired, OPCW/UN mission head Sigrid Kaag addressed the UN Security Council on the matter.

Although she did not believe the Syrians were deliberately stalling, she said co-operation must be speeded up if the June 30 deadline is to be met.

A second senior Western diplomat said it was possible that Western powers were overestimating Russia's leverage with Assad's government.

Still, Western nations are encouraging Moscow to use all its influence on Damascus to resume complying with the timetable agreed in September and October.

It is in Moscow's interests to ensure that the chemical weapons deal doesn't fall apart. Russia doesn't want its reputation as a diplomatic power tarnished, or Assad's government to face renewed threats of US air strikes at a time when the Syrian army appears to have an edge over the opposition militarily.

"Of course it is in Russia's interest to see it go ahead. President (Vladimir) Putin threw a safety belt to President Obama at a very delicate moment," said Georgy Mirsky, a Middle East expert at the Institute of the World Economy and International Relations in Moscow.

The US and Russia have invested political capital in the operation to eliminate Syria's 1,300 tonne stockpile, of which just 4.1 per cent had been handed over for destruction.

"If it appears now that it was all in vain - that chemical weapons will remain in Syria and that Bashar al-Assad is pulling a fast one - it will be President Putin who will be in a very bad situation indeed," Mirsky said.-Reuters