The U.S. Ambassador to Turkey, Jeffry L. Flake, on Thursday said the sale of F-16 fighter jets to Ankara will progress rapidly after President Tayyip Recep Erdogan signs off on Sweden’s NATO membership in the upcoming days.

In an interview, Flake said once a formal ratification document is received in Washington, the U.S. State Department will promptly send the US Congress notification of the $20 billion F-16s deal.

“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 US ambassador said.

The Turkish national assembly ratified Sweden’s NATO membership bid on Tuesday, lifting a major obstacle to the expansion of the military alliance after 20 months of delay. Turkey was unwilling to move forward, demanding the Scandinavian country crack down on Kurdish activists residing in Sweden, who according to Turkey had links with the PKK, a rebel group Turkey has dubbed a terrorist organization.

Turkey’s backing of Sweden’s NATO bid was linked by both Erdogan and members of the U.S. Congress with the approval of the $20 billion sale of the Lockheed Martin fighter planes 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.

The ambassador stated that he came into contact with the heads of the foreign affairs committees of the House of Representatives and the Senate of the United States, including those expressing concerns about the sale of F-16s to Turkey due to the country’s human rights record and delays in Sweden’s integration.