White House says some employees were fired by mistake

Hundreds of staff at the agency responsible for maintaining the U.S. nuclear stockpile were fired Thursday in the wave of mass Trump administration terminations, multiple current and former employees told ABC News.

The National Nuclear Security Administration ensures "the United States maintains a safe, secure, and reliable nuclear stockpile," according to its website. The agency also has a team of first responders that deploy to nuclear disasters around the globe and a counterterrorism division, which hunts down nuclear devices in the hands of U.S adversaries.

All of those key functions were impacted by the firings, ABC News' Jay O'Brien was told.

Multiple current and former employees described the situation as "a national security crisis."

Two former staffers confirmed probationary employees began receiving termination notices late Thursday and worried the agency of only about 1,800 employees was losing the key nuclear arms expertise that cannot be replaced.

-ABC News' Jay O'Brien

The Treasury Department's Office of Inspector General and the Government Accountability Office confirmed it will investigate reported access to the Treasury's vast payment systems by DOGE employees.

The Treasury's deputy inspector general wrote in a letter to lawmakers that she initiated an audit on Feb. 6 and they "expect to begin our fieldwork immediately."

"Given the breadth of this effort, the audit will likely not be completed until August; however, we recognize the danger that improper access or inadequate controls can pose to the integrity of sensitive payment systems. As such, if critical issues come to light before that time, we will issue interim updates and reports," the deputy inspector general added.

The letter came after Democratic senators last week raised concerns about DOGE's access to Treasury data.

-ABC News' Allison Pecorin

Ukrainian President Volodymyr Zelenskyy said the United States, including the Biden administration, never saw Ukraine as a NATO member.

Zelenskyy made the comments while speaking at the Munich Security Conference in Munich ahead of a planned meeting with Vice President JD Vance.

"I heard so many times from the American side, by the way, Biden's administration and now from President Trump. I heard a lot of messages from them by phone. My first phone call with President Biden and my first question, will we be in NATO? He said, no, no. And I said, we will see," Zelenskyy said.

"But to be very honest, United States, they never saw us in NATO. They just spoke about it. But they really didn't want us in NATO. It's true," Zelenskyy added.

Zelenskyy reiterated that if they cannot join NATO, they will build their own version within Ukraine. Zelenskyy said he doesn't "want to be that person in history who helped Putin to occupy my country."

In remarks to the Munich Security Conference, Vice President JD Vance made the argument to European lawmakers to pay attention to the interests of conservative voters as he criticized the continent's handling of defense spending, migration and censorship.

"The threat that I worry the most about vis-a-vis Europe is not Russia, it's not China, it's not any other external actor. And what I worry about is the threat from within, the retreat of Europe from some of its most fundamental values, values shared with the United States of America," Vance said.

Vance largely skirted around one of the biggest issues of the global conference: Ukraine. He briefly said that the White House believes they can "come to a reasonable settlement between Russia and Ukraine," but focused more on defense spending and issues of censorship and democracy.

Vance seemed to know that his remarks might bristle some in the audience. One Ukrainian member of parliament described it as "the total humiliation of all European leaders."

"People in the room are shocked," Oleksiy Honcharenko said in a post on X. "For most of Vance's speech, the European leaders and bureaucrats looked at each other, and there was almost no applause."

-ABC News' Michelle Stoddart and Zoe Magee