Donald Trump’s invitation to Russian spies to find lost emails routed through Hillary Clinton’s notorious private server was “irresponsible” and clearly underscores that “he cannot become our commander in chief,” former Defense Secretary and CIA Director Leon Panetta said on Wednesday.

“Think about that, Donald Trump, who wants to be president, is asking one of our adversaries to engage in hacking or intelligence efforts against the United States of America to affect an election,” Panetta told the Democratic National Convention.

“As someone who was responsible for protecting our nation from cyberattacks, it’s inconceivable that any presidential candidate would be that irresponsible,” he said, adding that it was “no time to roll the dice” on Trump and national security.

Earlier in the day, Trump, an admirer of Russian President Vladimir Putin, asserted in Florida, that he would like the Moscow government to obtain emails said to be missing when Clinton gave the FBI data from the private server installed in the basement of her New York home that she used while secretary of state from 2009-13.

“Russia, if you’re listening, I hope you’re able to find the 30,000 emails that are missing,” Trump said. “I think you will probably be rewarded mightily by our press.” FBI Director James E. Comey said earlier this month that by routing classified information through her personal server, Clinton and her aides were careless. He could not rule out the possibility that a hostile power hacked the account.