Hillary Clinton's campaign manager Robby Mook on Thursday blasted Donald Trump for calling on Russia a day earlier to track down Hillary Clinton's 30,000 missing emails.
"Inviting a foreign power that has, that is an aggressor at times towards the U.S. to commit espionage for whatever reason, let alone to influence the outcome of one of our elections is just unacceptable," Mook said in an interview on "CBS This Morning."
"This is unbecoming of a president of the United States. This further proves that he is unfit and does not have the temperament to serve," he added.
In an interview with Fox News' Brian Kilmeade, Trump claimed that he was just being sarcastic.
"Of course I'm being sarcastic. And they don't even know, frankly, if it's Russia. They have no idea if it's Russia, if it's China, if it's somebody else. Who knows who it is? But you have 33,000 e-mails deleted and the real problem is what was said on those e-mails from the Democratic National Committee. You take a look at what was said on those emails. It's disgraceful," Trump said.
Pointing out that Trump said he was joking, Mook said that the issue has "moved beyond politics and rhetoric" and it's "now a matter of national security."
Mook said Clinton's goal in her nomination speech Thursday night is to "make sure people know the facts."
"She's gonna talk about the choice the voters face in this election -- are we gonna succumb to these forces that are rigging the economy against everyday people that are tearing us apart and dividing us, or are we gonna work together to solve these problems and move this country in the future?" he said.
Mook would not say whether Clinton will specifically name the GOP presidential nominee in her speech and did not say whether she will address voters' concerns about trusting her.
He suggested that she was still working on her speech as of Wednesday night, saying she returned to it after her surprise appearance joining President Obama on the stage in Philadelphia after his convention speech.