Defense Secretary Pete Hegseth on Wednesday fired Navy Secretary John Phelan. 

Chief Pentagon spokesperson Sean Parnell said in a statement posted on X that Phelan is "departing the administration, effective immediately."

Phelan and Hegseth didn't work well together, and the decision was due to Phelan failing to follow orders and obey the chain of command, Axios reported, citing unnamed sources. 

In a post on Truth Social, President Donald Trump called Phelan a "long time friend" and said he did an "outstanding job" in his position. Trump also stated that Phelan had "decided to move on from his position." 

Undersecretary Hung Cao will become Acting Secretary of the Navy, Parnell said. 

The news comes in the midst of an ongoing naval blockade in the Strait of Hormuz, with both the U.S. and Iran attempting to stop ships from passing through the waterway that's vital to the global trade in petroleum and petrochemicals.