Washington on Tuesday reaffirmed its support of Turkey’s request to buy F-16 fighter jets and modernization of its fleet.

“We’ve been very clear about the F-16. That conversation about the F-16 and Turkey has been around for some time,” White House spokesperson Karine Jean-Pierre said at a press conference.

“We talked about this several months ago. So there’s really nothing new. The president has supported that effort,” Jean-Pierre added.

Her comments were in response to a question that pointed out the criticism of a group of Democratic lawmakers who opposed Biden’s remarks after his meeting last week with President Recep Tayyip Erdoğan.

In a press conference on the sidelines of the NATO summit in Madrid, Biden said Washington “should sell” F-16 fighter jets to Turkey, adding he was confident that the needed congressional approval would be obtained.

“We should sell the F-16 to Turkey. I said that in December, and my position hasn’t changed since then. It’s not in our interests not to sell them. We need congressional approval to get there, and I think we’ll get there,” he added.

Biden’s remarks marked Washington’s strongest public backing yet for the request since it was lodged by Ankara last October.

Turkey made a request to buy 40 Lockheed Martin-made F-16 fighters and nearly 80 modernization kits for its existing warplanes, in what is estimated to be a $6 billion deal.

A key Republican senator, Lindsey Graham, who visited Turkey over the weekend, reiterated his backing for the Biden administration’s decision.

“I will do all in my power to support the Biden Administration’s decision to sell F-16s to the Turkish Air Force,” Graham said on Twitter.

Graham dubbed the trip to Turkey “very productive,” stressing the country was a “member of NATO and a valuable American ally.”

“While we have had a problematic relationship at times, it is imperative Turkey and the US take steps to strengthen the ties between our two nations,” he wrote on Twitter.

Graham added that the fighter jets will bolster the Turkish military, which is “most definitely in America’s national security interests.”

Washington had not previously openly expressed any opinion on the sale aside from saying all weapons sales would have to go through the necessary legal process.

In March, the State Department wrote a letter to some members of the U.S. Congress who had opposed the sale, saying “appropriate” U.S. defense trade ties with Turkey would serve U.S. interests.

The sale of U.S. weapons to NATO ally Turkey became contentious after Ankara acquired Russian-made S-400 defense missile systems, triggering U.S. sanctions as well as Turkey’s removal from the F-35 fighter jet program.