U.S. lawmakers will vote - and likely pass - a defense bill later on Wednesday that calls for sanctions against Turkey over Ankara's decision to procure the S-400 defenses.
"The time for patience has long expired," Republican Lindsey Graham and Democrat Chris Van Hollen said.
Moscow hopes to seal a deal to supply Turkey with more S-400 missile systems in the first half of next year.
Qatar’s security and defense cooperation are the backbone of the Doha-Ankara alliance, Erdogan said. “We have deep relations in the Gulf.”
After the much anticipated meeting at the White House to address a crisis in relations, Trump said he was "a great fan" of the Turkish leader and that they had a "productive" encounter.
Republican Senator Rick Scott plans to unveil a resolution on Thursday calling for sanctions against Turkey after its purchase of a Russian air defense system.
Speaking symbolically on the third anniversary of the 2016 attempted coup against him, President Recep Tayyip Erdogan said that eight planes had landed with parts of the S-400.
Erdogan says delivery of system to be completed by April 2020.
US calls move "unacceptable."
The United States says the Russian military hardware is not compatible with NATO systems and that the acquisition may lead to Ankara's expulsion from an F-35 fighter jet program.