Donald Trump's top Army general has abruptly resigned as Pete Hegseth pushes to demote his command and purge the Pentagon's senior ranks, sidelining top officers with little explanation.

General Chris Donahue, 56, will step down as head of US Army operations in Europe and Africa, with his retirement expected to be announced as soon as Wednesday.

Donhue is a decorated officer who commanded the Army's elite Delta Force and amassed two decades of combat experience. He has long been seen inside the Army as one of its top leaders and a potential future chief of staff.

As commander of the 82nd Airborne Division during the 2021 US withdrawal from Afghanistan, Donahue was the last American service member to leave the country, captured in a now-famous night-vision image as he boarded a C-17.

His departure comes as Hegseth was preparing to downgrade Donahue's post from a four-star command to a three-star one, a source told ABC News.

Going from a four-star to a three-star post strips the command of the military's highest rank, signaling reduced prestige and authority. 

Four-star officers can only hold positions designated for that rank, so when no such command is available, early retirement is often the only option left.

The effort is reportedly part of Hegseth's broader plan to sideline and purge senior officials within the Pentagon. 

The abrupt departures and reassignments among senior Pentagon leaders under Hegseth has developed a pattern critics describe as an effort to clear out officials seen as insufficiently loyal.

The shake-up has intensified in recent weeks, with Hegseth moving against several high-ranking officers in the wake of the US military confrontation with Iran.

Hegseth routinely boasted that US forces held complete air and naval superiority over Iran, even as the regime kept control of the Strait of Hormuz for months.

Supporters cast the changes as overdue streamlining of a bloated general officer corps. 

Detractors warn that sidelining experienced commanders risks hollowing out the military's leadership at a volatile moment. 

In April, Hegseth forced out Army Chief of Staff General Randy George during the Iran war, along with the Army's chief of chaplains, Major General William Green Jr., and the head of Army Transformation and Training Command, General David Hodne.

George's removal followed repeated clashes with Hegseth, including over the secretary's decision to block the promotions of four Army officers

Those firings followed the ousting of more than a dozen generals and admirals since Hegseth took office, including Joint Chiefs Chairman General CQ Brown and Chief of Naval Operations Admiral Lisa Franchetti.

The Daily Mail has contacted the Pentagon for comment.

Lieutenant General Kevin Admiral is expected to be nominated by Hegseth to take over Donaue's role.

Donahue's departure from leading US army operations in Europe and Africa also comes as the US prepares to withdraw military support from European NATO allies. 

The Pentagon announced last week that it will conduct a six-month review of troop levels in Europe as it looks to scale back its military presence. 

The goal, according to Hegseth, is aimed at shifting more of the continent's defense onto European allies.

Along with evaluating the number of troops stationed in Europe, the Pentagon will also reduce the fighter jets, drones, warships, and submarines it keeps in the region for use in a war or crisis.