U.S. Democratic presidential nominee Hillary Clinton greets well-wishers as she arrives in Cleveland, Ohio, U.S., September 5, 2016. REUTERS/Brian Snyder

Democratic presidential nominee Hillary Clinton says that Donald Trump’s failure to spell out a plan to defeat the self-described Islamic State is “not only dangerous but should be disqualifying” for the office of the presidency.

During NBC’s Commander-In-Chief forum on Wednesday night ― the first event featuring both presidential candidates in question-and-answer sessions on national security ― Trump struggled to give a clear answer on his strategy to take on ISIS, claiming he both did and did not have a plan after more than a year of claiming he had a secret strategy for taking on the terrorist group.

“Last night was yet another test, and Donald Trump failed yet again,” Clinton said Thursday morning, in what was her first formal press conference in 278 days. She argued that Trump’s inability to offer a clear plan to beat ISIS, along with his comments denigrating American armed forces and praising Russian President Vladimir Putin, offered more proof that he was “temperamentally unfit and totally unqualified to be commander in chief.”

“That’s just not unpatriotic and insulting to the people of our country and commander in chief. It is scary because it suggests he’ll let Putin do whatever he wants to do, and then make excuses for him,” Clinton told reporters. “What would Ronald Reagan say about a Republican nominee who attacks American generals and heaps praise on Russia’s president?”

She added that every Republican in office should be asked if they agree with the real estate mogul on his views of Putin and his comments about U.S. generals, who Trump said have been “reduced to rubble” under the Obama administration.

Of Trump’s plan to take on ISIS, Clinton said “he still doesn’t have one.”

In yet another bid to attract more Republicans to her campaign, the former secretary of state announced she would hold a “working session” on terrorism on Friday with a number of high-profile former national security officials, including retired U.S. Marine Corps Gen. John Allen, former Homeland Security Secretary Michael Chertoff, former Deputy Director of the Central Intelligence Agency Michael Morell, former Homeland Security Secretary Janet Napolitano and former CIA Director David Petraeus.

Jason Miller, Trump’s senior communications director, issued a statement denouncing Clinton’s remarks as “desperate attacks of a flailing campaign sinking in the polls, and characteristics of someone woefully unfit for the presidency of the United States.”