Turkey’s stance on its S-400s hasn’t changed, even as the United States appeared to dangle support in Syria in exchange for Ankara abandoning the controversial Russian missile defense systems, Turkish Foreign Minister Mevlut Cavusoglu said Tuesday.

“It is not appropriate to put preconditions when an ally is in need, an urgent need, like [is] happening in Idlib,” said Cavusoglu during a webinar hosted by the Atlantic Council and the Turkish Heritage Organization.

Earlier this month, US ambassador to NATO Kay Bailey Hutchison suggested a package to assist Turkey’s military operations in northwest Syria was conditioned on Ankara rejecting the missile defense system, which she said was “deterring some of the capabilities that we would be able to give [Turkey] to fight against the Syrian aggression.”

Turkey’s acquisition of two Russian-supplied surface-to-air missile systems remains a source of friction between the two NATO allies. In early March, US Syria envoy James Jeffrey said that the S-400 issue left US officials split over whether to provide further support to Turkey in rebel-held northwest Syria.