ISTANBUL, Jan 25 (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 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 $20 billion F-16s sale.

urkey’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 would be published in Turkey’s Official Gazette. The instrument of accession for Sweden also needs to be sent to Washington.