A top Defense Department official affirmed Turkey's "military modernization needs in support of NATO," the Pentagon said on Wednesday.

The department's acting Assistant Secretary of Defense for International Security Affairs Laura Cooper also "highlighted cooperation on the Black Sea" during a United States-Turkey high-level defense group dialogue session at the Pentagon, spokesperson Lt. Col. Anton Semelroth said in a statement. Cooper is serving as the Pentagon's lead for the discussions.

The Tuesday meeting between U.S. and Turkish delegations "discussed a wide range of functional and regional issues. This included transnational priorities, such as defeating terrorism, and regional security in Afghanistan, Africa, South Caucasus, Eastern Mediterranean and the Middle East," Semelroth said.

A follow-up meeting in Ankara was agreed upon by both sides, according to the Pentagon. It did not list a date.

The high-level meeting between military delegations in the United States was held in a positive and constructive atmosphere, the Turkish defense ministry also announced on Wednesday, saying that the next meeting will be held in Turkey.

The delegations discussed bilateral and regional security issues as well as the F-16s issue, the ministry said in a written statement.

One of the top agendas of the two countries recently has been the S-400 crisis.

Turkey will have to consider alternatives to ensure its security if the United States takes a negative approach towards a deal for F-16 fighter jets, Defense Minister Hulusi Akar said Tuesday.

Turkey requested to buy 40 F-16s and nearly 80 modernization kits in return for the payment Ankara had allotted for the F-35 fighter jet program.

"If the U.S.’ stance is negative, Turkey will necessarily and naturally have to evaluate other alternatives in order to ensure its security in the threat environment in which it is located," said the minister.

Turkey had paid $1.4 billion (TL 14.34 billion) for the F-35s before Washington expelled it from the program in 2019 over its purchase of a Russian-made S-400 air missile defense system after its efforts to acquire U.S.-made Patriot missiles were rebuffed.

Ankara has been demanding reimbursement for its payment and has said it should be used to finance some of its requests to buy F-16s and modernization kits.

Still, any military sales would have to be approved by the U.S. Congress, known for its anti-Turkey stance that has repeatedly damaged bilateral relations.

During their meeting on the sidelines of the G-20 summit in Rome earlier this month, President Recep Tayyip Erdoğan said he had asked his U.S. counterpart Joe Biden for support in getting U.S. lawmakers to back the sale.

Erdoğan said he had seen a "positive approach" from Biden on Turkey’s request. "While I saw Mr. Biden’s positive approach on this matter, another aspect of the issue is the House of Representatives and Senate," he added.

Washington can approach the issue positively, Akar said, adding: "However, we are closely following developments (on the issue), as the process will be subject to congressional approval."

In case the deal on F-16s fails, Ankara is still ready to consider purchasing Russian-made Su-35 and Su-57 fighter jets, officials have said.

Ankara had ordered more than 100 F-35 jets, made by Lockheed Martin, while its defense industry has been a prominent player in the development and manufacturing of fighter jets.