The head of the agency responsible for designing, building, storing and testing the U.S. nuclear arsenal recently gave senior personnel an unusual warning about leaking classified information.

The Nov. 22 memo, first reported by the New York Times and confirmed to USA TODAY by a source with knowledge of its content, came from Brandon Williams, the administrator of the National Nuclear Security Administration. Williams, a former Navy submarine officer and one-term Republican congressman representing western New York, took the reins at NNSA in late September.

Williams' "urgent" admonition about leaking classified info was framed as "an order," according to the Times, and appealed to the oaths of office that government personnel swear upon beginning their duties.

The new administrator, who lacks the deep technical experience of some of his nuclear physicist and retired senior military predecessors, is a key figure in President Donald Trump's ambiguous push to restart nuclear weapons testing.

Trump and the White House have repeatedly refused to clarify whether the president intends to order explosive nuclear tests − whether full scale or extremely small scale in nature − which would upend a nearly three-decade period where none of the world's major powers is confirmed to have detonated a nuke.

The White House has previously said that Trump's directive to the Department of Energy and Pentagon is to test nuclear weapons on an "equal basis" as rivals like Russia and China. The State Department has accused Russia of conducting extremely small-scale nuclear explosions at a remote Arctic archipelago where testing historically occurred, and China has expanded its historical nuclear testing grounds in recent years as well.

The memo against leaking came days after a Nov. 14 CNN story reported that Williams, Energy Secretary Chris Wright, and directors of the U.S. national laboratories planned to meet with Trump at the White House in an effort to dissuade him from resuming explosive nuclear tests.

Although Williams told lawmakers in his April confirmation hearing that he would advise against resuming explosive nuclear weapons testing, administration officials, in the wake of the CNN report, said all options were being considered.

An NNSA spokesperson reached via email told USA TODAY that the agency does not comment on internal memos.

Davis Winkie's role covering nuclear threats and national security at USA TODAY is supported by a partnership with Outrider Foundation and Journalism Funding Partners. Funders do not provide editorial input.

This article originally appeared on USA TODAY: Trump's nuke chief issues 'urgent' warning about information leaks

Reporting by Davis Winkie, USA TODAY / USA TODAY

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