The United Nations has said the departure of a team of chemical weapons inspectors to Syria was "imminent" following a green light from Damascus.
"The Government of Syria has formally accepted the modalities essential for cooperation to ensure the proper, safe and efficient conduct of the mission," UN Secretary-General Ban Ki-moon's spokesman said in a statement on Wednesday.
The UN statement said "the departure of the team is now imminent," but it provided no specific date.
The team led by Swedish arms expert Ake Sellstroem would investigate the sites of alleged chemical attacks for a period of at least two weeks, the statement said.
Ten experts from the Organization for the Prohibition of Chemical Weapons and the World Health Organization will also be part of the team.
But diplomats and chemical weapons experts have raised doubts about whether they will find anything since the alleged incidents took place months ago.
Also, the mandate of the investigation is limited as experts will report on whether chemical weapons were used, and if so which ones, but they will not determine the responsibility for the attack, Reuters said.
The Syrian opposition says the investigators can have full access to sites under its control where chemical weapons are alleged to have been used.
The mission has been delayed in the past over differences with President Bashar al-Assad's regime over the scope of the probe into the alleged use of chemical arms in the country's civil war.
The United Nations last month reached a framework agreement with the Syrian government on the mission, but had been awaiting a final approval from Damascus.
One of the sites to be investigated is Khan al-Assal, near Aleppo, where the government says rebels used chemical weapons on March 19, killing at least 30 people, including 16 Syrian soldiers.
The opposition says government forces carried out the attack.
The UK, France and the US followed with allegations of chemical weapons use in Homs, Damascus and elsewhere.
UN Middle East envoy Robert Serry told the Security Council last month that the UN has received 13 reports of alleged chemical weapons use in Syria.
On June 13, Washington said it had conclusive evidence that Syrian regime had used chemical weapons against opposition forces. That crossed what President Barack Obama had called a "red line" and prompted a US decision to send arms and ammunition to the opposition.
The conflict in Syria, which erupted more than two years ago, has left almost 100,000 people killed, according to UN figures.