Veterans listen as Republican presidential candidate Donald Trump speaks during the Commander in Chief Forum. The security forum was hosted by NBC on Wednesday in New York.

NEW YORK — Donald Trump and Hillary Clinton confronted their key weaknesses in a televised national security forum, with the Republican defending his preparedness to be commander in chief despite vague plans for tackling global challenges and the Democrat arguing that her controversial e-mail practices did not expose questionable judgment.

Trump also renewed his praise of Russian President Vladimir Putin and his disdain for President Barack Obama, saying that the Russian enjoyed an 82 percent approval rating. “The man has very strong control over a country,” Trump said. “It’s a very different system and I don’t happen to like the system, but certainly, in that system, he’s been a leader, far more than our president has been a leader.”

Speaking to reporters in Laos, Obama said today that Trump confirms his belief that Trump isn’t qualified to be president “every time he speaks” and added: “The most important thing for the public and the press is to just listen to what he says and follow up and ask questions to what appear to be either contradictory or uninformed or outright wacky ideas.”

Trump and Clinton spoke back-to-back Wednesday night, each fielding 30 minutes of questions. While the candidates never appeared on stage together, the session served as a preview of sorts for their highly-anticipated presidential debates.

By virtue of a coin flip, Clinton took the stage first and quickly found herself responding at length to questions about her years in government. She reiterated that she had made mistakes in relying on a personal e-mail account and private server as secretary of state and in voting for the 2003 invasion of Iraq as a senator. But she defended her support for U.S. military intervention to help oust a dictator in Libya, despite the chaotic aftermath.

“I’m asking to be judged on the totality of my record,” said Clinton, who grew visibly irritated at times with the repeated focus on her past actions.

Clinton, who has cast Trump as dangerously ill-prepared to be commander in chief, tried to center the discussion on her foreign policy proposals. She vowed to defeat the Islamic State group “without committing American ground troops” to Iraq or Syria. And she pledged to hold weekly Oval Office meetings with representatives from the Pentagon.

Trump did little to counter the criticism that he lacks detailed policy proposals, particularly regarding the Islamic State group. He both insisted he has a private blueprint for defeating the extremist group and that he would demand a plan from military leaders within 30 days of taking office.

But he also was harshly critical of the military, saying America’s generals have been “reduced to rubble” under Obama. Asked to square his request for military options with that criticism, Trump said simply: “They’ll probably be different generals.”

With just two months until Election Day, national security has emerged as a centerpiece issue in the White House race. Both candidates believe they have the upper hand, with Clinton contrasting her experience with Trump’s unpredictability and the Republican arguing that Americans worried about their safety will be left with more of the same if they elect Obama’s former secretary of state.