The parties at the Syrian peace talks in Kazakhstan have agreed the boundaries of the final de-escalation zone, Turkish and Russian diplomatic officials said Friday.

Axar.az reports citing AA.

Officials from Turkey, Russia and Iran have agreed the borders of the zone in the northern province of Idlib and are negotiating over which monitors will be deployed, the officials said on condition of anonymity due to restrictions on talking to the media.

Idlib is the main opposition-held area in Syria. The borders of three other zones across the country were agreed earlier.

The three guarantor states, as well as representatives of the Damascus regime and some opposition factions, are meeting in Kazakhstan’s capital Astana for a sixth round of talks aimed at ending the six-year conflict.

The UN’s special envoy on Syria Staffan de Mistura and delegates from Jordan and the U.S. are attending as observers. According to the Kazakhstan Foreign Ministry, Qatar is also participating for the first time as an observer.

Turkey, which supports some opposition groups, and Russia and Iran, which back President Bashar al-Assad’s regime, have been holding talks in Kazakhstan since January.

They are seeking to implement lasting cease-fires in areas where fighting has been heaviest between opposition forces and pro-Assad troops.

As well as Idlib, the zones are due to be established in parts of the Latakia, Aleppo, Hama and Homs provinces, eastern Ghouta and Damascus, as well as areas of Deraa and Al-Quneitra.

The agreement would see a cessation of fighting on the ground as well as an end to airstrikes.

The release of detainees, the return of bodies and the search for missing persons are also on the agenda at the two-day meeting.