UN Secretary-General Ban Ki- moon cut short a European visit to return to UN headquarters Thursday to await a preliminary report from chemical weapons investigators who are due to complete work in Syria this weekend, a UN spokesman said here.

The team will wrap up, as scheduled, its 14-day stay in Syria on Saturday morning, associate UN spokesman Farhan Haq told reporters.

"Any reports of the alleged incidents of the use of chemical weapons that are brought to the secretary-general's attention by a member state will be given serious consideration," said Haq.

The UN team, led by Swedish specialist Ake Sellstrom, was initially set to investigate the March 19 alleged chemical weapons attack on Khan al-Asal in the Aleppo region and two other sites of alleged chemical attacks. They later headed to the Damascus suburb of Ghouta, where chemical weapons were allegedly used on Aug. 21, to collect evidences.

The team "gathered quite an extensive amount of material in recent days to go to laboratory testing and that will occur at several different sites in Europe. Some of the inspectors will be on hand for all the various deliveries to the various laboratory sites to insure the chain of custody and they will wait for the laboratory analysis to be completed," Haq said.

"Once the secretary-general is back, in fact he will be back tonight (Thursday), starting (Friday) he will try to reach out to member states and take discussions forward on questions of what's happening in Syria," he said.

There were no immediate plans for a UN Security Council meeting, which can be called for any time of day or night, he added.

"The investigators intend to put together an evidence-based narrative of what the facts show," the spokesman said. "And those facts should help you get to the bottom of what happened Aug. 21 at Ghouta."

"What the secretary-general made clear was .. he wants all the parties to give diplomacy a chance," Haq said. "He wants all the parties on the ground and in the region as a whole to take seriously the effort to get the parties together for negotiations including through the Geneva II conference which we have been trying to arrange for many months now."

As for when that report from the team would be available, Haq said, "It's something that would take longer than days but it is the clear intention of the investigation team to finish its work as soon as it possibly can."