Washington: Donald Trump fuelled more controversy on Wednesday when he encouraged Russia to meddle in the presidential campaign, even as he dismissed suggestions from Obama and other Democrats that Moscow was already acting on his behalf.
On the heels of reports that Russia may have hacked Democratic Party emails, Trump said, "Russia, if you're listening," it would be desirable to see Moscow find and publish the thousands of emails Clinton says she deleted during her years as secretary of state.
To Obama and Clinton, Trump's comments only fed their contention that the billionaire businessman is unqualified to be commander in chief. Trump has no national security experience and few ties to the norms that have governed US foreign policy under presidents from both parties, including standing by NATO allies threatened by countries including Russia.
Read: Russians possibly trying to sway US polls: Obama on DNC emails hack
Hillary Clinton's campaign lashed out at Donald Trump for encouraging Russia to trawl the former secretary of state's emails, describing his comments as a "national security issue".
"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. This has gone from being a matter of curiosity, and a matter of politics, to being a national security issue," said top Clinton advisor Jake Sullivan.
The FBI concluded earlier this month that Clinton had been "extremely careless" in her handling of classified material via a private email server, but did not recommend that she face criminal charges.
Read: Hillary Clinton refutes FBI charge that she was ‘careless’ with emails
The Clinton campaign's explosive accusation of inviting foreign spying came as US intelligence agencies pointed to Russia as the cause of a mass hack of Democratic Party emails.
Clinton's camp believes that Moscow gave the mails to WikiLeaks, which released them last week, to foment unease between the former first lady and her one-time Democratic rival Bernie Sanders.
The scandal caused the resignation of Democratic Party leader Debbie Wasserman Schultz and poured kerosene on Democratic infighting at a party convention in Philadelphia.
Read: Democratic Party chair resigns after Hillary Clinton email leak
Trump has adopted a number of pro-Russian policy positions as a presidential candidate, suggesting he would recognize Moscow's annexation of Crimea and lift economic sanctions.
His campaign chair's close ties with pro-Russian politicians in Ukraine has also raised allegations that Trump is too cozy with Moscow and its powerful leader Vladimir Putin.
Read: FBI director to face Congress over Clinton email investigation
"I have nothing to do with Putin," Trump said. "Never spoken to him. I know nothing about him other than he will respect me."
"If it is Russia. Nobody knows. It's probably China, or it could be somebody sitting in his bed. But it shows how weak we are. It shows how disrespected we are," he said.
Trump's vice-presidential running mate Mike Pence quickly tried to limit the fallout from the mogul's comments.
"The FBI will get to the bottom of who is behind the hacking. 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 ," he said in a statement.
"Donald Trump, who wants to be president of the United States, is asking one of our adversaries to engage in hacking or intelligence efforts against the United States of America to affect our election," Leon Panetta, Obama's former Pentagon chief, said in his convention address.
