US President Donald Trump said he did not blame Turkey for buying a Russian missile defense system, prompting his administration to exclude NATO allies from the F-35 fighter jet program.

Trump, speaking to reporters at the White House, did not elaborate when he would decide to impose sanctions on Turkey for dealing with the Russian military, as required under the US 2017 Penal Code.

“We are looking at the whole situation of Turkey … It’s a difficult situation … I do not blame Turkey because there are many circumstances,” Trump said.

Turkish President Recep Tayyip Erdoğan said on Friday his country would go to buy fighters from elsewhere if the United States did not sell its F-35 fighter jets.

He added that the US decision to exclude Turkey from the program of production of these fighters will not deter them from seeking to meet their needs.

US lawmakers said they were unhappy with Turkey’s acquisition of Russia’s S400 missile defense system, but they were not too sure what Trump or Congress should do next, suggesting that efforts to impose sanctions were not a priority at the moment.