ASTANA, May 4. /TASS/. Russia will do everything possible to ensure that warplanes are not used in de-escalation zones in Syria, Head of Russia’s Delegation and Russian Presidential Envoy on the Syrian Settlement Alexander Lavrentyev said on Thursday. 

A memorandum on the establishment of de-escalation zones in Syria was signed in Astana on Thursday.

"The Syrian Foreign Ministry has stated that the leadership of that country welcomes the agreements on creating de-escalation zones and ceases its aviation flights over them," the diplomat said.

"We express the confidence that after such a statement the flights by Syrian combat aircraft and their operation on the territory of de-escalation zones will cease," the envoy said.

"As for the flights by aircraft of the Russian Aerospace Force, we will naturally cease combat operations on this territory but only if no efforts are taken from the territory of de-escalation zones to destabilize the situation on the country’s other territories," Lavrentyev said.

"Russia is ready to take part by sending its observers to the so-called safety line zones to participate in monitoring compliance with the ceasefire and to fix violations," said Alexander Lavrentyev.

The memorandum on the de-escalation zones in Syria envisages the cessation of hostilities in the designated areas as of May 6, he went on.

"All hostilities in the areas tentatively designated by our military experts will stop as of May 6," he said. De-escalation zones in Syria established for half-a-year with possibility to extend the term.

"From the sixth day, all hostilities will cease on the territories preliminarily defined by our military experts," he said.

"Further observance of the ceasefire will largely depend directly on armed opposition formations staying in de-escalation zones and also on terrorist organizations, first of all, Jabhat al-Nusra [outlawed in Russia] whose presence on these territories is quite considerable," the envoy said.

As the Russian envoy said earlier, Moscow came up with a proposal to establish the so-called de-escalation zones as it believed that this "can really help resolve the old problem of separating the Syrian moderate opposition from terrorist organizations.".