Syria can still meet a June deadline for getting rid of its chemical weapons, but to do so must resume stalled weapons transfers now, an international coordinator told the UN Security Council Thursday.

Syria has suspended the transfers for what it says are security reasons, but on Sunday said it planned to resume them in the "coming days."

Sigrid Kaag, coordinator for the international operation to eliminate Syria's chemical weapons stockpile, warned the council any further delay would make it "increasingly challenging" to stick to the June 30 deadline, according to diplomats.

"Assuming that operations restart immediately, operations could be achieved on time," diplomats quoted her as saying.

"I have repeated to Syrian authorities the need for a swift resumption of the removal operation. Operations have to restart immediately," she said.

Damascus agreed to give up its chemical weapons in September under a deal to ward off the threat of US air strikes.

The agreement was reached after deadly chemical attacks outside Damascus last August that the West blamed on the regime of President Bashar al-Assad.

Kaag said there were 72 containers filled with chemical weapons ready to be transferred to the main Syrian port of Latakia for shipment out of the country.

Their removal from Syria would account for 90 percent of the country's stockpile, she said.

So far nearly 54 percent of the Syrian chemical arsenal has been disposed of.

A UN spokesman, Farhan Haq, urged Damascus "to resume movements as soon as possible to meet the timeline for the complete removal and destruction of chemical weapons."

Syria, which has missed a number of key deadlines, has blamed the delays on a lack of security caused by its three-year-old civil war.

Diplomats said US Ambassador Samantha Power and her French counterpart Gerard Araud also insisted that Damascus accelerate the removal of the remaining weapons, and cannot use security issues as an "excuse."

"Security should not be an excuse for delay. It should be a motive for speeding up removal," Power was quoted as saying.

Russia, however, said Syria had already given up more than half its arsenal and that the Syrian forces protecting the convoys moving the weapons had been the target of attack north of Latakia.

Bashar Jaafari, Syria's representative to the United Nations, called the situation around Latakia "alarming" and blasted the "terrorist groups" fighting his nation's military.

"Fights continue between the Syrian Army and terrorist groups who crossed the border from Turkey," said Jaafari, who said the combatants also have the support of Saudi Arabia, Qatar, Al Qaeda and its affiliate Al-Nusra Front.

"The deadline set up by the Syrian government and OPCW (Organization for the Prohibition of Chemical Weapons) can not be respected fully unless the security situation evolves in the right direction," Jaafari said.

"Those with influence on those terrorist groups should do their best to guarantee that the convoys carrying the chemical material and the port at Latakia will not be attacked."