Turkish President Recep Tayyip Erdogan today laid out his agenda for Saturday talks with Vice President Joe Biden, saying a Russian military build-up in northern Syria, which reported involves “up to 200” Russian troops, is threatening to Turkey and “won’t be tolerated.”

Erdogan expressed particular concern about reports of a team of Russian military engineers arriving in Qamishli, in Hasakeh Province, to investigate the possibility of expanding the runway and capacity of the airport to serve as a Russian air base in northeastern Syria.

The US has recently taken over a base in the same area of Hasakeh from the Kurdish YPG, and Russia seems keen to get a base there as well, as they’ve similarly backed the YPG against ISIS. Erdogan, however, insisted that “There is no difference between PYD, YPG, PKK, or ISIS.”

If the meeting ends up focusing on Russia, the likelihood is that the US will back more NATO deployments into southern Turkey, and probably push for more troops along Russia’s borders in Eastern Europe too just so the Baltic states don’t feel left out. In practice, Turkey’s government may insist it won’t “tolerate” Russia having a base in Kurdish northeast Syria, but can’t actually do anything about it.