US State Department spokeswoman Morgan Ortagus said Ankara would face "real and negative consequences" for acquiring Russian S-400 defence systems.
Turkey called on the United States on Wednesday to avoid steps that can harm bilateral relations after the US State Department said Ankara would face "real and negative consequences" for acquiring Russian S-400 defence systems.
"Those consequences include participation in the F-35 programme," State Department spokeswoman Morgan Ortagus told reporters on Tuesday.
Turkey's foreign ministry spokesman Hami Aksoy said the comments by Ortagus were not in line with the spirit and content of talks between presidents of the two countries at the G20 summit last month in Japan.
"We invite the US side to avoid taking steps, excluding diplomacy and dialogue, that will harm relations," Aksoy said, adding Ankara had still not received a response to its proposal to set up a working group to look into the impact of the S-400 purchase.
US President Donald Trump accepted at the G20 Summit that Turkey had been treated unfairly by the Obama administration which did not allow Ankara to buy Patriot missiles.
"You can't do business that way. It's not good," Trump said.