Hillary Clinton’s latest mishandling of sensitive information may have occurred before an audience of 70 million.

Speaking at the presidential debate Wednesday night, Clinton noted that it takes four minutes from the time the president makes the call to use nuclear weapons to their actual launch. The remark came amid questions about the fitness of Clinton and GOP candidate Donald Trump to hold the nation’s nuclear codes, but critics, including former intelligence operatives, told Fox News that level of detail about nuclear response times is “protected information.”

“The bottom line on nuclear weapons is that when the president gives the order, it must be followed,” Clinton said. “There’s about four minutes between the order being given and the people responsible for launching nuclear weapons to do so.”

"Whether the four minutes is accurate or not, anything having to do with response capability is generally classified," Dan Maguire, a former strategic planner with Africom, and with 46 years combined service, told Fox News. "She has a tendency to use previous access and her position as secretary (of state) to give an appearance of knowledge to show she has the answers, rather than protect the information."

The reference to a four-minute timeline between the order and the launch was seen by former intelligence officers and military operatives as a possible violation of operational security, known as OPSEC.

A former Navy SEAL officer said the statement appears to be a "direct violation of US national security protocols and governing law. Our country has no greater secrets than those that protect our strategic nuclear deterrence capability."

Clinton, who was investigated by the FBI for a year for “careless” handling of sensitive and even top secret emails on her private server, went on to say that 10 people who have had the responsibility of carrying out such a presidential order are backing her.

A senior official in the Clinton campaign rejected claims the former secretary of state revealed any secret information, and provided Fox News with multiple published reports detailing the response time. In one Bloomberg News article, Bruce Blair, a former Minuteman missile-launch officer and research scholar at Princeton University’s Program on Science and Global Security, spelled out the step-by-step procedure that follows an order from the president. The procedures include conferring with military and civilian advisers in Washington and around the world including the head of all U.S. strategic nuclear forces at Strategic Command in Omaha.

That meeting can be as deliberative and lengthy as the president wants, but if the decision is prompted by the knowledge that a hostile nation has launched nuclear weapons at the U.S., it could last a matter of seconds, according to Blair.

“About five minutes may elapse from the president’s decision until intercontinental ballistic missiles blast out of their silos, and about fifteen minutes until submarine missiles shoot out of their tubes,” the news article stated. “Once fired, the missiles and their warheads cannot be called back.”

Intelligence experts, including the former Navy SEAL and a former senior intelligence official told Fox News that the mere fact the response time has been reported in academic documents does not authorize government officials who hold a security clearance, or had previous access to classified information, to discuss it publicly.

Clinton’s statement "now validates with specificity something of great sensitivity that has long been speculated by our adversaries and others in the national arena, including academics and think tanks, " the former SEAL officer said.

At a Pentagon press conference with South Korean defense minister Han Min-Koo, Defense Secretary Ash Carter avoided the issue when asked about this by CNN’s Barbara Starr.

"I’m sorry but I’m not gonna answer your first part because it is cast in terms of the ongoing presidential campaign,"  Carter said. "I’ve said repeatedly I’m not going to not answer questions in that context."

Two senior defense officials reached by Fox News highly doubt Clinton was read into any nuclear response plans as secretary of state and think the “four-minute” comment was an estimation on her part, not a classified number she revealed.

"While the excuse has been given that there has been previous 'talk' in the media and in academia regarding the 4 minute response time, it was just that – talk – it was informed speculation or assumption – it was not confirmed or stated by any official U.S. government official or stated as policy," Tony Shaffer, Vice President for Strategic Initiatives and Operations at the London Center for Policy Research, told Fox News.  

"There is uncertainty  - for a reason – maintained by the Department of Defense- so that adversaries do not know what our capability is or what to expect – that has been blown here by Ms. Clinton," Shaffer added. 

Catherine Herridge is an award-winning Chief Intelligence correspondent for FOX News Channel (FNC) based in Washington, D.C. She covers intelligence, the Justice Department and the Department of Homeland Security. Herridge joined FNC in 1996 as a London-based correspondent.