By Jonathan Spicer

ISTANBUL (Reuters) – The U.S. ambassador to Turkey said he anticipates that President Tayyip Erdogan will give a final sign-off on Sweden’s NATO membership within days, triggering rapid steps toward U.S. Congress endorsing a sale of F-16 fighter jets to Ankara.

In an exclusive interview on Thursday, Ambassador Jeff Flake said that once the formal ratification document is received in Washington, the U.S. State Department will immediately send Congress notification of the F-16s sale.

Turkey’s parliament ratified Sweden’s NATO membership bid on Tuesday, clearing a major hurdle to expanding the Western military alliance after 20 months of delay.

Erdogan needs to sign the legislation, which then would be published in Turkey’s Official Gazette. The instrument of accession for Sweden also needs to be sent to Washington.

Asked whether he expected this “within days”, Flake, a former U.S. Republican senator, told Reuters: “Yes, I do.”

“I see no reason why, with the parliament having acted here, that Turkey would wait,” he said. “So I would expect as soon as that is conveyed to Washington, then congressional notification (of the F-16 sales) will happen.”

“The president here needs to sign it and then the instrument needs to be conveyed to Washington,” he told Reuters by phone. “As soon as that happens, then we expect notification to happen. And official notification will happen.”

Both Erdogan and members of the U.S. Congress had tied Turkey’s backing of Sweden’s NATO bid with congressional approval of the $20 billion sale of Lockheed Martin aircraft and modernization kits to Turkey.

U.S. President Joe Biden sent a letter to leaders of key Capitol Hill committees on Wednesday informing them of his intention to begin the formal notification process for the F-16 sale once Ankara completes Sweden’s NATO accession process.

(Reporting by Jonathan Spicer; Editing by Mark Potter)