Syrian rebel commanders say they expect Turkey's operation to implement the so-called de-escalation zone in the northwestern province of Idlib "to go smoothly" and without much resistance from Hay'et Tahrir al-Sham.

Idlib is largely controlled by the Hay'et Tahrir al-Sham alliance, or Tahrir al-Sham, a Salafist group dominated by a former al-Qaeda affiliate, al-Nusra Front.

"Turkey has made it clear to Tahrir al-Sham, through representatives from the armed opposition groups including Faylaq al-Sham, that any factions who put up a fight would be targeted," rebel commander Musa Khaled told Al Jazeera.

Speaking from Idlib, Khaled said that although there may be fighting in some areas, Hay'et Tahrir al-Sham "understands that they do not have the military capability" to fight the Turkish army.

"This will cause them to submit to any deal that is enforced on them," he said.

READ MORE: Syria's 'de-escalation zones' explained

A Turkish military delegation entered Idlib late on Sunday to assess the ground situation and prepare to enforce the so-called de-escalation zones finalised by Turkey, Russia and Iran in a deal struck at the Kazakh capital, Astana, on September 15.

The establishment of the zones in areas including Idlib was aimed at halting fighting and offering safety to civilians.

Hay'et Tahrir al-Sham was not part of the talks and rejected the plan to implement such zones.

The delegation entered under the supervision of the Faylaq al-Sham and Nour al-din al-Zinki rebel groups, and with the knowledge of Hay'et Tahrir al-Sham, according to rebels.

The Turkish military unit managed to reach al-Sheikh Barakat mountain, west of Aleppo on the southern border with Turkey, which overlooks Idlib.

"The Turkish armed forces began reconnaissance activities on October 8 to establish surveillance posts as part of the operation to be carried out in Idlib province," the Turkish Armed Forces said in a statement on Monday.

As part of the September 15 deal, Turkey is working with rebels it backs on the ground, mainly the Free Syrian Army.

Hisham Eskeif, from the political office of the Hamza Division, a rebel group affiliated with the Free Syrian Army, said there is a "principal, momentary understanding" between the Turkish army and Tahrir al-Sham.

"The Turks are being clear - they don't want blood to be spilled - and they're trying to get that across to Tahrir al-Sham," Eskeif told Al Jazeera.

On Sunday, Turkish President Recep Tayyip Erdogan told members of his ruling AK party that Turkey's "efforts in Idlib are ongoing, in cooperation with the Free Syrian Army, without any problems at the moment".

Since January, Turkey, along with Russia and Iran, has been spearheading the efforts to end the six-year war in Syria.

READ MORE: Syria's civil war explained from the beginning

While the conflict started as a largely unarmed uprising calling for the downfall of Syrian President Bashar al-Assad, widespread demonstrations quickly slipped into civil war after the government responded with force and as opposition groups comprising army defectors and civilians took up arms.

Although armed opposition groups, backed mainly by Turkey and the Gulf states, were making major gains in the first few years of the war, Russia's intervention in 2015 in support of Assad drastically turned the tide in favour of the government.

The Turkish-Russian-Iranian initiative is the latest and most serious attempt at implementing a solution to the conflict.

More than 465,000 Syrians have been killed in the fighting, more than a million injured, and over 12 million - half of the country's prewar population - have been displaced from their homes.