UN leader Ban Ki-moon will review an accord struck with Syria on investigating the use of chemical weapons before any details are announced, a UN spokeswoman said Saturday.

Ban will meet in New York on Monday with the two envoys who struck the accord, spokeswoman Morana Song told AFP.

The UN and Syrian government said in a joint statement issued late Friday that an accord had been reached "on the way forward" in the investigation, following the visit to Damascus by Ake Sellstrom, head of the UN inspectors, and Angela Kane, the UN disarmament envoy.

The statement did not say whether UN inspectors would be allowed into Syria as Ban has demanded.

"Ms. Kane and Dr. Sellstrom are expected to report to the secretary general on Monday on the result of their visit to Syria," Song said.

"We will have no further comment until the secretary general has had an opportunity to get briefed on the visit and review the situation," she added.

Kane and Sellstrom were in Damascus on Wednesday and Thursday. They met with Foreign Minister Walid al-Muallem and deputy prime minister Qadri Jamil, said the joint statement.

"The discussions were thorough and productive and led to an agreement on the way forward," the joint statement added, without giving any other detail.

The UN says it has been given reports of 13 chemical weapons attacks during the 28-month old conflict.

Ban has demanded widespread access to investigate all allegations. Syria has insisted the UN only investigate its claim that opposition rebels used chemical weapons in the town of Khan al-Assal on March 19.

Britain, France and the United States say all the attacks were carried out by President Bashar al-Assad's forces. Russia, Assad's main ally, says its inquiry found opposition rebels used sarin gas in Khan al-Assal.