WASHINGTON — Former Vice President Mike Pence on Tuesday criticized his former boss-turned-rival, Donald Trump, for calling retired Gen. Mark Milley, the former chairman of the Joint Chiefs of Staff, a traitor over phone calls he made to China in the final stormy months of their administration.

“Frankly what Donald Trump said about him in that tweet, about treason and death, was utterly inexcusable,” Pence said at a national security and foreign policy forum at Washington’s Georgetown University.

Pence also reacted to the news that House Speaker Kevin McCarthy had been ousted from his post by a contingent of hard-right conservatives, saying, “Chaos is never America’s friend.”

The event was the first in a series of conversations with 2024 Republican presidential candidates on the topic co-hosted by The Associated Press and Georgetown’s Institute of Politics and Public Service.

Trump, in a recent social media post, lashed out at Milley over calls he made to his Chinese counterpart to assure him that the United States was not going to suddenly go to war with or attack China. Trump called the conversations “an act so egregious that, in times gone by, the punishment would have been DEATH! A war between China and the United States could have been the result of this treasonous act.”

Milley has defended the calls as “routine” and “perfectly within the duties and responsibilities” of his job.

Still, Pence, who said he hasn’t agreed with all of the policies put in place during Miley’s tenure, declined to respond to Milley saying in his retirement speech that, “we don’t take an oath to a wannabe dictator” — a comment widely interpreted to be about Trump.

“I wouldn’t have a comment on that characterization or who he was alluding to,” he said.

Pence has positioned himself as a relative foreign policy hawk in the crowded GOP primary and repeatedly railed against the growing tide of isolationism in his party. He has accused rivals like Trump and his followers of abandoning U.S. allies and argued the only way to keep America safe is by engaging with the world.

“America is the leader of the free world. If we’re not leading the free world, the free world is not being led,” he said Tuesday.

The contrast between Pence and others in the party has been particularly stark on Ukraine. The former vice president has called on the Biden administration to deliver more military aid to the country as it fights Russia’s invasion and has criticized those in his party who question the need for ongoing U.S. involvement.

“I believe that if Vladimir Putin and the Russian military overruns Ukraine, it will not be long before they cross the border of a NATO country where our men and women in uniform would be required to go and fight,” he said.