Defense Secretary Pete Hegseth, Secretary of State Marco Rubio and Gen. Dan Caine, chairman of the Joint Chiefs of Staff, are scheduled to brief top lawmakers known as the “Gang of Eight” behind closed doors on Tuesday, three officials told ABC News.

Separately, Sen. Roger Wicker, the Republican chairman of the Senate Armed Services Committee, told reporters that he expects to speak this week with Adm. Alvin Holsey, who unexpectedly announced this fall he was stepping down as head of U.S Southern Command after less than a year on the job. It was not immediately clear how Holsey would meet with the lawmakers, and if it would be in person or virtual.

The Gang of Eight briefing by President Donald Trump’s national security team follows the completion of the administration’s national security strategy, a planning document that spells out America’s long-term vision for protecting the nation. But lawmakers also were expected to raise questions about the legality of military strikes in the Caribbean and, in particular, the killing of two survivors from a lethal attack on Sept. 2.

Holsey’s upcoming discussion with lawmakers is an indication that some lawmakers are quietly pursuing their own probe into the boat strikes and Hegseth’s orders to the uniformed military.

Sources said that before Holsey announced his retirement, he had expressed concerns to Hegseth’s team about military operations in the Latin America region, although it was not clear whether he had reservations about the legality of the campaign. Hegseth has insisted that the strikes are legal, including those that killed the two survivors last September.

Last week, a Pentagon official told ABC News that he was “asked to retire on good terms.” Holsey’s last day in uniform is Friday. He served 37 years in uniform.

The Gang of Eight refers to the chairs and ranking members of the House and Senate intelligence committees, along with House and Senate minority and majority leaders, including House Speaker Mike Johnson and Senate Majority Leader John Thune.