Washington - US Navy Secretary John Phelan has been removed from his post in an abrupt shake-up at the Pentagon as Washington grapples with rising tensions with Iran and an ongoing maritime standoff in the Gulf, raising fresh questions about stability within the defence leadership.
Pentagon spokesperson Sean Parnell confirmed the move in a brief statement, saying Phelan was "departing the administration, effective immediately". He will be replaced on an acting basis by Hung Cao, a former Navy captain and Republican political candidate.
Phelan's exit makes him the first service secretary to depart during Donald Trump's second term but follows a broader pattern of dismissals and resignations among senior defence officials.
The timing of Phelan's departure has raised questions in Washington, coming as the US Navy plays a central role in enforcing a blockade on Iranian ports and targeting vessels linked to the Islamic Republic during a tenuous ceasefire.
Phelan had appeared in public just a day earlier, addressing a major Navy conference and meeting lawmakers to discuss shipbuilding plans and budget priorities, underscoring how unexpected the move was.
The Navy is currently maintaining an elevated global posture, with multiple aircraft carriers deployed or heading towards the Middle East, alongside operations in the Caribbean and elsewhere.
While no official explanation has been given, US media reports suggest internal disagreements may have contributed to the decision. According to Axios, a source familiar with the situation said Phelan had clashed with defence secretary Pete Hegseth and was seen as overstepping his role.
The report cited concerns that Phelan had bypassed established chains of command by communicating directly with Trump. Another source described tensions between the two men, saying they "did not get along".
Phelan, a businessman and major Trump donor, had no prior military or civilian leadership experience in the Navy before his appointment and was widely viewed as an outsider brought in to drive change.
His exit follows a series of high-profile dismissals under Hegseth, who has moved to reshape military leadership since taking office. In recent weeks, the defence secretary removed the Army's top officer, Gen. Randy George, and previously dismissed senior figures including Adm. Lisa Franchetti and Gen. Charles "CQ" Brown Jr., the former chairman of the Joint Chiefs of Staff.
The changes have fuelled debate over the stability of Pentagon leadership during a period of heightened global tensions.
The leadership reshuffle comes as the US faces a growing confrontation with Iran, centred on control of key maritime routes including the Strait of Hormuz.
Tehran has imposed restrictions on shipping in response to what it describes as an unlawful US naval blockade, while Washington has continued to target Iranian-linked vessels. The standoff has disrupted global energy flows and raised fears of further escalation.
Iranian officials have also pointed to divisions within the US military leadership. Mohammad Baqer Qalibaf previously criticised the dismissal of senior US generals, suggesting it reflected disagreements over Washington's military strategy.
Cao, who will serve as acting Navy secretary, is a 25-year Navy veteran who served in special operations roles in Iraq, Afghanistan and Somalia. A refugee from Vietnam as a child, he later pursued a political career, running unsuccessfully for Congress and the Senate in Virginia.
He has aligned closely with Trump-era defence priorities, including opposition to diversity initiatives in the military and support for reinstating service members dismissed over Covid-19 vaccine mandates.
Phelan's abrupt exit adds another layer of uncertainty to US defence leadership at a time when military operations and geopolitical tensions are intensifying.
With a ceasefire hanging in the balance and maritime confrontations ongoing, the turnover at the top of the Pentagon underscores the challenges facing the administration as it seeks to manage both internal divisions and external crises.