"The differences of opinion in Syria shouldn't affect Turkey-Russia relations. The situation in Idlib will not affect the S-400 agreement," broadcaster NTV reported Turkish Foreign Minister Mevlut Cavusoglu as saying.

Turkey purchased the Russian S-400 air defence system despite opposition from NATO ally the United States and the threat of sanctions.

Rebel backer Turkey and Damascus ally Russia have worked closely on Syria although they are on opposite sides of the war.

Cavusoglu met with Russian Foreign Minister Sergei Lavrov on the sidelines of the Munich Security Conference and, in a tweet, described their meeting as "positive".

Cavusoglu said that a Turkish delegation would go to Moscow on Monday. "(We) agreed on making an evaluation after these meetings," the Turkish minister added.

A Russian delegation including military and intelligence officials had already held talks in Ankara last weekend, but no concrete agreement emerged.

The ministers talks was the highest-level meeting between Turkish and Russian officials since tensions over Idlib began after Damascus killed 14 Turks this month.

The Turkish military has 12 observation posts in the northwestern province of Idlib, the last rebel-held bastion in Syria.

The posts were set up after a 2018 Russia-Turkey deal agreed in Sochi to prevent a regime offensive but in recent months, Syrian President Bashar al-Assad has pressed an assault supported by Russian air strikes.

After the Turks' deaths, Ankara and Moscow became embroiled in a war of words over who had not fulfilled the conditions of the Sochi deal.

Earlier on Saturday, Turkish Vice-President Fuat Oktay insisted Ankara had "fulfilled its responsibilities" after Russia accused Turkey of failing to "neutralise terrorists" in Idlib.

Turkish President Recep Tayyip Erdogan previously accused Russia of committing "massacres" in its support of the Syrian government.

The United Nations says 800,000 people have fled the region since December.