Ankara: Turkey on Wednesday warned the United States against taking the "wrong steps" after the US State Department said there would be consequences if Ankara bought Russia's S-400 missile defence system.
"We are inviting the US to avoid taking the wrong steps which would exclude diplomacy and dialogue and harm relations," the foreign ministry said in a statement.
It comes after the US renewed its warning to Ankara that there would be "real and negative" consequences if it completes the purchase of the S-400.
"Those consequences include participation in the F-35 program," State Department spokeswoman Morgan Ortagus told reporters on Tuesday.
She said that Turkish officials were fully aware of the Countering America's Adversaries Through Sanctions Act, a law passed by Congress in 2017 that mandates sanctions for any "significant" purchases of weapons from Russia.
President Recep Tayyip Erdogan had said after meeting US counterpart Donald Trump last month that he was confident Turkey would not face sanctions for buying the S-400.
The Turkish foreign ministry said the State Department warning did "not match the content and the spirit" of the Trump-Erdogan meeting on the margins of the G-20 summit in Japan.
"The conditions that prompt Turkey to acquire S-400 are apparent," it added.
Trump, after meeting Erdogan, appeared convinced by the Turkish leader's assertion that former president Barack Obama did not allow Ankara to buy Patriot missiles.
"You can't do business that way. It's not good," Trump said.
Washington has threatened to remove Ankara from its F-35 fighter jet programme, giving Ankara until July 31 to cancel the S-400 purchase or have its pilots kicked off the training course and expelled from the US.
Turkey has proposed to form a working group with the US to address the issue. "But we have not yet received a response to our proposal," the ministry said.
Meanwhile, Turkey on Wednesday vowed to continue drilling activities off Cyprus despite tensions with the European Union, which has called on Ankara to cease its "illegal" activities.
The discovery of huge gas reserves in the eastern Mediterranean has sparked a dispute between EU member Cyprus and Turkey, which last month sent a second ship, the Yavuz, to search for oil and gas in the region.
"The drilling activities of our ship Yavuz are based on legal and legitimate grounds," the Turkish foreign ministry said in a statement. "We reject the statement made by Greek Foreign Ministry and EU officials that deem our country's activities illegal," it added.
In May, Ankara sent the ship Fatih into Cyprus' exclusive economic zone to begin drilling there, while the Yavuz was deployed last month to search for oil and gas to the east.
The European Union said in a statement on Monday that a second attempt by Turkey to drill for oil and gas was an "unacceptable escalation", having already warned Ankara to stop its "illegal" activities or face sanctions.
The European Council said it was considering "appropriate measures" and would respond "in full solidarity with Cyprus" in light of the second exploration. The United States and Egypt also joined a chorus of criticism this week, with Washington urging Turkish authorities "to halt these operations".
Ankara says its actions abide by international law and
that it is drilling inside its continental shelf.