US President Donald Trump hinted at the resignation of Defense Secretary James Matisse during a 60-minute interview with CBS News.
Trump said he was not sure whether Matisse was planning to resign, but added he might do so.
The president said he considered Matisse "somewhat democratic".
"If you want to know the truth, I think he is somewhat democratic, but General Matisse is a good person, we are working very well together, he may resign," he said, according to an excerpt from the interview broadcast on Sunday.
Nicky Healy is the last member to resign from the Trump team as new US ambassador to the United Nations.
He joins a long list of senior employees who have left the Trump administration, including former Secretary of State Rex Tilerson, who was sacked in March, and Steve Bannon, chief strategist at Trump, who stepped down in August 2017.
