In comments that appeared to condone the hacking of sensitive US correspondence, Republican presidential nominee Donald Trump on Wednesday said he hoped Russia locates missing e-mails sent by Hillary Clinton when she was US secretary of state.

"Russia, if you’re listening, I hope you’re able to find the 30,000 e-mails that are missing," Trump said during a news conference. "I think you will probably be rewarded mightily by our press. Let's see if that happens. That'll be nice."

At the same event, Trump also said, "I'm not gonna tell Putin what to do. Why should I tell Putin what to do?... It's not even about Russia or China or whoever it is that's doing the hacking. It's about the things they said in those e-mails. They were terrible things." A video of the entire news conference is here.

The comments come six weeks after Democratic National Committee officials disclosed a hack on their network that lasted for almost a year . The breach, which security experts and US intelligence officials say was likely conducted by Russian spies, exposed opposition research, donor information, and almost a year's worth of private e-mails. Some of the data was published last week on WikiLeaks , touching off disarray in the weekend leading up to the Democratic Party's convention and prompting the resignation of DNC Chair Debra Wasserman Schultz. Russian spies have also been implicated in a hack of a White House unclassified network in 2014.

Critics wasted no time blasting Trump's statement that he hoped Russia found the e-mails Clinton has failed to produce during her tenure as secretary of state.

"This has to be the first time that a major presidential candidate has actively encouraged a foreign power to conduct espionage against his political opponent," Clinton's chief foreign policy advisor, Jake Sullivan, said, according to a New York Times article . "This has gone from being a matter of curiosity, and a matter of politics, to being a national security issue."

Later, Trump posted a tweet that said: "If Russia or any other country or person has Hillary Clinton's 33,000 illegally deleted emails, perhaps they should share them with the FBI!"