Turkish and Russian officials agreed Friday to start joint patrols in Syria's Idlib at the weekend, Turkey's defence minister said, following a fragile ceasefire in the last rebel stronghold.

"Both sides have signed the prepared text, and it has entered into force. We will see the first application of this with joint patrols on March 15 along the M4 highway," said Hulusi Akar, quoted by state news agency Anadolu.

A Russian military delegation has been in Ankara since Tuesday to work out the details of a ceasefire agreed on March 5 in Moscow between Turkish President Recep Tayyip Erdogan and Russian counterpart Vladimir Putin.

The accord stated that a security corridor with joint Turkish-Russian patrols would be established along the key M4 highway of the northwestern province. "Joint coordination centres will be set up with Russia where the activities will be managed together," the minister added.

Akar repeated Turkey's wish for the ceasefire to be "lasting". Idlib had suffered heavy bombardment by Syrian forces and Russian warplanes since December, killing hundreds of civilians and forcing nearly a million to flee towards the Turkish border.

Despite being on opposing sides of the nine-year war, Turkey and Russia have worked closely on Syria, especially regarding developments in Idlib. Turkey supports certain rebel groups in Idlib and has military observation posts under a previous ceasefire deal agreed with Russia in 2018.