LONDON — Russia on Friday announced it had dispatched two state-of-the-art warships to the Middle East after an attack in Syria killed 33 Turkish soldiers.

Videos posted on social media showed two of Russia’s newest guided missile frigates, the Admiral Grigorovich and Admiral Makarov, making their way through the Bosporus, a Turkish-controlled chokepoint that runs through Istanbul, on their way to the Syrian coast.

Though Russia and Turkey have seen a rapprochement in recent years, much to the chagrin of the U.S. and its NATO allies, the two sides pursue opposing goals in Syria: Moscow backs Syrian President Bashar al-Assad, while Ankara backs rebel groups opposing him in northern Syria.

Turkey has beefed up its support — both in men and materiel — for rebel forces in the face of a Syrian regime assault on the last remaining opposition stronghold in Idlib province. The escalation of violence has again highlighted Russia and Turkey’s irreconcilable aims in Syria.

The Russian Defense Ministry said Friday that the Turkish forces in Idlib came under Syrian government fire while operating alongside “terrorist formations” near the settlement of Behun, referring to Turkish-backed rebels.

“[Russian forces] have constantly requested and confirmed with their Turkish colleagues the coordinates of the location of all units of the Turkish armed forces positioned near the areas of terrorist actions,” the Russian statement said.

The statement said that Turkey failed to notify Russia that its troops were operating in the region while simultaneously denying that any Russian aircraft were conducting air strikes in the region.

Russian Foreign Minister Sergei Lavrov, speaking at press conference Friday, expressed his condolences for the Turkish soldiers, but noted that the incident would have been prevented if Ankara honored a de-confliction agreement between the two militaries in the region. He also said Presidents Vladimir Putin and Recep Erdogan have spoken about the situation.

The deployment Friday of Russian ships, capable of firing guided cruise missiles at land targets, comes as Turkey mulls over possible responses to the killing of its soldiers by Russian-backed Syrian forces on Thursday— including the possibility of a wider Turkish assault on Syrian forces in Idlib.

Military tensions last flared in 2017, when Turkey shot down a Russian aircraft that strayed into Turkish airspace while conducting bombing runs on Ankara-backed rebel forces in north-western Syria, raising the specter of broader conflict between Europe’s two largest militaries.

Turkey ultimately backed down from that standoff and signed on to purchase Russian S-400 air defense systems. Since then, Presidents Vladimir Putin and Recep Erdogan have made a show of fostering closer ties – at the expense of Turkey’s relations with NATO.

But now, with tensions again flaring with Russia, Erdogan is looking West for support. At Turkey’s request, NATO will be holding a meeting to consult with Ankara on the situation in Syria on Friday.

Reuters contributed to this report.