Republican US presidential nominee Donald Trump has made an extraordinary plea for a foreign power to locate the 30,000 missing emails from Hillary Clinton's private email server, saying they would reveal "some beauties".
"Russia, if you're listening, I hope you're able to find the 30,000 emails that are missing," Mr Trump said at a press conference in Miami. "I think you'll be rewarded mightily by our press."
Mrs Clinton's campaign claims that Russia hacked computers belonging to the Democratic National Committee (DNC) and released those emails on the eve of the party's convention to benefit Mr Trump's candidacy.
The emails, published by WikiLeaks last week, revealed that the DNC favoured Mrs Clinton's candidacy over rival Bernie Sanders, triggering a leadership shake-up within the DNC.
Mr Trump dismissed the claims, saying it is not clear who hacked those emails, but said the incident is a sign that foreign countries no longer respect the US.
"If it's any foreign country, it shows how little respect they have for the United States," said Mr Trump, who added that he was "not an email person myself because I believe it can be hacked".
Mr Trump's running mate Mike Pence condemned the possible cyber-espionage, breaking from Mr Trump for the first time since being selected as his vice president.
"If it is Russia and they are interfering in our elections, I can assure you both parties and the United States government will ensure there are serious consequences," Mr Pence said in a statement.
Mr Trump, whom Democrats have accused of having cosy ties with Russian president Vladimir Putin, repeatedly declined to condemn the actions of Russia or any other foreign power of trying to intervene in the US election.
"No, it gives me no pause," the celebrity businessman said. "If Russia or China or any of those countries gets those emails, I've got to be honest with you, I'd love to see them."
The Clinton campaign immediately denounced Mr Trump's call.
"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," senior policy adviser Jake Sullivan said in a statement.
"That's not hyperbole, those are just the facts. This has gone from being a matter of curiosity, and a matter of politics, to being a national security issue."
Mr Trump also suggested that Mrs Clinton should not receive any security briefings due to the hack that would ensure "that word will get out".
Mr Trump has said that he has "zero investments" in Russia and insisted that his company had not received any significant investments from the country.
He has also downplayed his affection for Mr Putin and said he would treat the Russian leader "firmly", though he said he wanted to improve relations with Russia.
Some Democrats and security experts have said that Mr Trump's proposal to set conditions on Nato allies could risk Russian expansion in Eastern Europe.
US president Barack Obama, meanwhile, said "anything's possible" when asked during an interview whether the Russians could be working to sway the election towards Mr Trump.
"Donald Trump has repeatedly expressed admiration for Vladimir Putin," Mr Obama said during the interview with NBC News that aired on Tuesday. "And I think that Trump's gotten pretty favourable coverage back in Russia."
Trump: "Russia, if you're listening, I hope you're able to find the 30,000 [Clinton] emails that are missing." https://t.co/4D6idLU47t— ABC News (@ABC) July 27, 2016