Russian Foreign Minister Sergei Lavrov on Wednesday warned of the risks of Washington sending mixed signals on an American withdrawal from northern Syria as the Kurdish administration there called up civilians to defend the region against a feared Turkish assault.
"We announce three days of general mobilization in northern and eastern Syria," the administration said in a statement, urging all civilians to "head to the border with Turkey... to resist during this delicate historical moment".
It also called on Kurds in Syria and abroad to protest against Ankara's planned offensive.
Ankara’s offensive is believed to be imminent.
The Kurds are "extremely alarmed" by US statements and fear that confusion could "ignite the whole region,” said Lavrov on Wednesday.
"This must be avoided at all costs," he said following talks in Kazakhstan's capital Nur-Sultan.
US President Donald Trump has blown hot and cold since a surprise announcement on Sunday that Washington was pulling back 50 to 100 "special operators" from Syria's northern frontier.
The troops had served as a buffer preventing a long-planned attack by Turkey against Kurdish forces, who were crucial in the campaign to defeat ISIS but are viewed as "terrorists" by Ankara.
After appearing to give a green light to the Turkish invasion on Sunday, he later threatened to "obliterate" Turkey's economy if it went too far.
On Tuesday, Istanbul sent more armored vehicles to the border with Syria, an AFP correspondent said, with a large convoy of dozens of vehicles seen in the Turkish town of Akcakale in Sanliurfa province.