Inside the Biden administration's push to get Sweden into NATO and F-16s to Turkey

A full-court press by the Biden administration in the days leading up to the NATO summit capped months of behind-the-scenes diplomacy to get Turkey to move ahead with Sweden's accession to NATO.

A major part of that diplomatic effort: Getting progress on the potential sale of F-16 fighter jets to Ankara - a request that, despite claims by top US officials, had become linked to the question of Sweden's membership to NATO.

The sale of the US arms to Turkey is not a done deal, and the key opponent, Senate Foreign Relations Committee Chairman Bob Menendez, told CNN on Tuesday afternoon that "as of now" he remains opposed.

The New Jersey Democrat has long been against selling the fighter jets to Ankara, not only due to Turkey's roadblocks for Sweden's membership, but also its human rights issues and regional aggressions including its tensions with Greece.

However, there are indications that efforts to shift Menendez's position and address his concerns have had some impact.

New details reported by CNN show how months of steady diplomacy, helped along by the close relationship of two former Senate colleagues, resulted in what could become one of the biggest foreign policy accomplishments of the Biden administration.

Now all eyes are on a meeting on Wednesday between Turkish President Recep Tayyip Erdogan and Greek Prime Minister Kyriakos Mitsotakis to see if the two leaders can do enough to assuage the US lawmaker's concerns and gain the approval of the F-16 sale.