"You don't sell F-35s [to Turkey]. Very well. But then we will take our own measures and look for other options," Erdogan told a meeting of provincial heads of his ruling Justice and Development (AK) Party in the capital Ankara.
He said Washington did not deliver to Turkey the jets pledged during the term of former U.S. President Barrack Obama.
"They said: 'Our congress did not allow'," Erdogan said, referring to the U.S. Congressmen.
"You rejected when we wanted to buy Patriot [missiles] during the Obama era. You are trying to prevent it again during Mr. Trump's era. We would like to purchase it but you don't want to give it. Then what are we going to do? We will buy it from whoever sells it."
U.S. President Donald Trump reportedly told Republican senators during a closed-door White House meeting Tuesday that he does not want to penalize Turkey for buying the Russian S-400 air defense systems.
Trump has repeatedly voiced reluctance to penalize Turkey over its purchase of the S-400s, including last week when announcing Ankara's removal from the F-35 fighter jet program. Turkey's expulsion is slated to be completed by the end of March 2020.
The Trump administration has maintained that the S-400 could expose the advanced fighter to possible Russian subterfuge and is incompatible with NATO systems.
Turkey, however, counters that the S-400 would not be integrated into NATO systems and would not pose a threat to the alliance.
Trump blames the Obama administration for the current row over its refusal to sign a deal with Turkey to sell it the American Patriot missile system, causing Ankara to seek Russia's support in the purchase of S-400s.
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