Turkey on Thursday said it would oust the Syrian Kurdish Peoples Protection Units (YPG) from the center of Afrin in northern Syria "in a very short time", as pro-Ankara forces surrounded the city. Turkey says the YPG is a "terrorist" offshoot of the outlawed Kurdistan Workers Party (PKK), which has been waging an insurgency inside Turkey since 1984. Ankara on January 20 launched a military operation dubbed Olive Branch to support Syrian rebels against the YPG in its enclave of Afrin. "The circle is closing in around the terrorists. We anticipate that the center of Afrin will be cleared of terrorists in a very short time, God willing in the coming days," Turkish presidential spokesman Ibrahim Kalin said. The rebels and Turkish troops closed in on the main city on Wednesday. Kalin told state broadcaster TRT in an interview that the offensive had secured 70 percent of the territory of Afrin district. He said that Ankara had no intention of handing over the town to the Syrian regime following the completion of its military offensive in the region. The US, which has worked closely with the YPG in the fight against militants, has urged restraint and the operation has increased tension between Turkey and its NATO ally.  But following a visit by outgoing US Secretary of State Rex Tillerson last month, the two countries said they would work together to solve a dispute over the control of the YPG-held Syrian town of Manbij.  Turkey has repeatedly warned it could extend its Afrin operation to Manbij, where the US military has a presence, and even further beyond that towards the Iraqi border. Turkish Foreign Minister Mevlut Cavusoglu was due to visit Washington on March 19 but the ministry said the visit had been postponed after Tillerson was fired by US President Donald Trump, who nominated CIA director Mike Pompeo as his replacement. Kalin insisted the change would not affect agreements with the US over Manbij that have yet to be made fully clear.