Updated

New Jersey Gov. Chris Christie lashed out at Democratic frontrunner Hillary Clinton on Thursday, saying her use of a private email server “put American intelligence officers at risk,” and that she had been motivated by convenience.

"She did it for convenience, for her convenience," Christie said. "She put America's secrets at risk for her convenience. She put American intelligence officers at risk for her convenience.”

He added: “Hillary Rodham Clinton did that to our country she is not qualified to be president of the United States.”

Christie, a former federal prosecutor who has made similar comments about Clinton in the past, argued he would be the best candidate to square off against Clinton in a general election.

Christie is among the seven top-polling Republican candidates on the prime-time stage in Des Moines, Iowa.

Thursday’s Fox News/Google debate is the final opportunity candidates will have before the Iowa caucuses Monday.