The meeting between Turkish Chief of Staff Hulusi Akar, US Chairman of the Joint Chiefs of Staff Joseph Dunford and Russian Chief of General Staff Valery Gerasimov appears to be the first of its kind.
Their discussions in the southern Turkish city of Antalya come as a US-led coalition is making progress to push the Islamic State group (IS) out of Syria, where Ankara has been increasing its efforts against the jihadists.
Turkey, Russia and the United States are all fighting against IS, though they support different camps and military tension remains because of Turkish opposition to the involvement of Syrian Kurdish militia.
Turkey has said that the next target of its cross-border Syria campaign would be Manbij, which is now controlled by the US-backed Syrian Democratic Forces (SDF), a group dominated by Kurdish fighters.
The SDF has controlled Manbij since last year when it pushed out IS, but recently it has clashed with Turkish-backed forces.
"Common issues relating to regional security, in particular Syria and Iraq, are being discussed at the meeting," the Turkish army said in a statement, without giving further detail.
Antalya has previously hosted several NATO meetings, as well as the G20 summit in 2015.
Moscow confirmed the meeting, with the defence ministry saying in a statement to Russian news agencies: "A joint discussion on security issues in Syria and Iraq is planned."
The Antalya talks are aimed at ensuring better coordination to avoid "the risk of unwanted clashes" as many countries are involved in Syria, the Turkish premier said.
'Common threat: terror'
Speaking in Ankara, Yildirim said Syria needed to be rid of "all terrorist groups" including Al-Nusra, Syrian Kurdish militia as well as IS jihadists.
"The objective of the meetings today and tomorrow (Wednesday) is how to provide coordination in the best way possible and prevent parties from interfering with each other's operations and cause unpleasant developments while fighting against terror," Yildirim said.
"Naturally terror elements are a common threat and spoil peace and (the possibility of) political solution in Syria."
The trilateral meeting in Antalya comes a day after Turkey stepped back from threats to unilaterally strike Kurdish militia deployed in Manbij.
"It makes no sense to launch an operation in Manbij without the cooperation of Russia and the United States," Yildirim said in a televised interview late on Monday.
His announcement stood in stark contrast to previous threats from Ankara that it would hit Syrian Kurdish militia -- considered "terrorists" by Turkey -- unless they withdrew from Manbij.
However on Tuesday Yildirim criticised some allies' "unfortunate" choice of Kurdish militia linked to separatist rebels in Turkey as partners against terror groups.
The Pentagon said it has sent extra troops into northern Syria to make sure competing forces in and around Manbij remain focused on fighting IS rather than each other.
Erdogan to meet Putin
Ankara has conducted a military campaign inside Syria since late August, backing Syrian opposition fighters and recapturing from IS several towns near its border including Jarabulus, Al-Rai, Dabiq and Al-Bab.
But the Turkish campaign is also aimed at stopping the advance of the Kurdish militia, which Ankara accuses of being the Syrian branch of an outlawed militant group.
Turkey has also said it wants to work with its allies to capture the IS stronghold of Raqa, but has ruled out any operation alongside the Kurdish militia.
Turkey is also cooperating with Russia in Syria, despite them being at odds politically over the future of Syrian President Bashar al-Assad, whom Moscow backs militarily.
Turkish President Recep Tayyip Erdogan plans to visit Russia on March 10, to co-chair with Russian counterpart Vladimir Putin a meeting of ministers from both countries, a statement from Erdogan's office said.
Bilateral ties as well as regional and international issues particularly Syria will be discussed, it added.
Eyewitness? Submit your stories now via social or:
Email: news@pulselive.co.ke
