The departure of the inspectors team led by Swedish chemical weapons expert Ake Sellstrom "is now imminent," Ban's office said in a statement two weeks after announcing Syria agreed to let the U.N. team investigate three sites where chemical weapons may have been used.
The world body said July 31 the U.N. inspectors would leave to inspect the sites as soon as possible.
But after nearly two weeks of delays, Ban's office said Tuesday the visit was further delayed because U.N. and Syrian negotiators hadn't reached an agreement on measures to ensure the team's safety.
A day after releasing that statement, Ban's office said the regime of President Bashar Assad "formally accepted the modalities essential for cooperation to ensure the proper, safe and efficient conduct of the mission."
Assad's regime agreed the team would "remain in the country to conduct its activities, including on-site visits, for a period of up to 14 days, extendable upon mutual consent," Ban's office said.
One site to be visited is the Khan al-Assal district of Aleppo, where the Assad regime alleges Syrian rebels used chemical weapons March 19.
The two other locations to be visited were not announced.
Sellstrom's panel has received unconfirmed evidence 13 sites in Syria were subjected to chemical weapons use. His panel's purpose is to determine if such weapons were used, not who used them.
Assad and the rebel opposition have both accused each other of deploying chemical weapons in the conflict, which is nearly 3 1/2 years old and has left more than 100,000 Syrians dead.