Russian media are confirming reports that they are in the process of a naval buildup off the coast of Syria, sending additional frigates through the Bosphorus into the area. This is being called the largest naval presence Russia has had in the Mediterranean since 2015.

This comes as the US adds warships to the coastal area as well. Russia noted in particular that the USS Ross, armed with Tomahawk missiles, was deployed to the area recently. This comes amid repeated US threats to attack Syria.

Russia has been warning the US against attacking Syria again, while US officials continue to reiterate threats if there is a “chemical attack.” Those threats take on a whole additional seriousness amid reports Islamist rebels in northern Syria are planning to “stage” such an attack so the US will intervene again.

NATO made no mention of the US ships in the area, but issued a statement calling on Russia to “exercise restraint” with its own ships, and faulting them over the humanitarian problems inside Syria.