US President Donald Trump is considering lifting sanctions on Turkey and resuming the sale of fighter jets after talking to President Recep Tayyip Erdogan.

Trump has expressed his intention to help finalize the sale of F-16 fighter jets to Turkey and is open to the idea of selling Turkey its true target, F-35 fighter jets, if the two sides can come to an agreement that would render Russia's S-400 system inoperable, Fox News reported, citing sources.

Trump's team has requested a legal and technical analysis of how it could avoid recognizing Turkey as a violator of the Countering America's Adversaries Through Sanctions Act (CAATSA), according to one source familiar with the request.

The U.S. has agreed to extend an exemption allowing Turkey to buy Russian natural gas through May, Bloomberg reported Thursday.

Trump and Erdogan spoke by phone on Sunday, and the Turkish government is set to firm up plans for Erdogan to come to the U.S. to meet with Trump in the near future.

The Turkish embassy pointed to a recording of the phone call from Erdogan's office that said the Turkish president addressed Trump saying, “In order to develop cooperation between the two countries in the defense industry, it is necessary to lift CAATSA sanctions, complete the F-16 procurement process and Turkey's participation in the F-35 program.”