Former Secretary of State John Kerry on Friday denounced President Trump’s threatening posts about Iran as sounding like the “prelude to becoming one of the greatest war criminals in history.”

Kerry told MS NOW’s Jen Psaki on “The Briefing” that the president’s Truth Social posts –– an expletive-laden post on Sunday and a Tuesday threat that Iran’s “whole civilization will die” –– left him “as shocked as I’ve been by anything that I have seen or read by this administration, in the first administration and now in the second.”

“We’re the place that, you know, worked so hard to liberate Europe or free Europe from fascism and so many other contributions we’ve made around the world,” he continued. “And you step up and not only use language like that, but say a whole civilization is going to die. That sounds to me like it’s a prelude to becoming one of the greatest war criminals in history.”

The former secretary added that when “you kill a civilization, you are doing something precisely against all of the international norms, standards, values and hopes and aspirations.” Kerry then referenced his time protesting the Vietnam War after he served as a lieutenant in the U.S. Navy, saying that “when life and death is involved, and war is involved … you really need to tell the truth.”

Kerry dismissed the Trump administration’s claim that there was an “imminent nuclear threat” from Iran.

“There just wasn’t an imminent threat. And even the administration spent months telling us they have obliterated the entire program,” he said, referring to the U.S.-Israeli strikes on Iran’s nuclear sites in June.

Trump resumed his threats toward Iran later in the week, ahead of negotiations to be held between Iranian officials and a U.S. delegation led by Vice President Vance in Pakistan. The president on Friday told the New York Post he was ready to resume strikes if talks between both countries are not successful.

“We’re going to find out in about 24 hours,” he told the outlet. “We’re going to know soon. We have a reset going. We’re loading up the ships with the best ammunition, the best weapons ever made — even better than what we did previously, and we blew them apart.”

He later told the Post that “if we don’t have a deal, we will be using them, and we will be using them very effectively.”

Trump’s “whole civilization” threat came with an 8 p.m. EDT deadline on Tuesday for Iran to offer a peace deal and reopen the Strait of Hormuz. A deal was reached with hours to spare, kicking off a two-week ceasefire and the reopening of the strait.

Iran shut down the strait the next day, citing Israel’s heavy attacks on Lebanon. Iranian officials and Pakistani Prime Minister Shehbaz Sharif have said the ceasefire extends to Lebanon, a point disputed by Trump administration officials and Israeli Prime Minister Benjamin Netanyahu.

Copyright 2026 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

For the latest news, weather, sports, and streaming video, head to The Hill.