Hillary Clinton and one of her most prominent backers once again raised Donald Trump's ties to Russia Friday and suggested the GOP presidential candidate would be subject to bribery by top U.S. adversaries.

Clinton raised the issue in Pittsburgh, in the heart of battleground Pennsylvania, after billionaire supporter and Dallas Mavericks owner Mark Cuban took the attack even further in his own remarks introducing Clinton, who narrowly leads Trump in the Rust Belt state.

'Imagine having a president who owes hundreds of millions of dollars to foreign banks and other foreign entities that he doesn't tell us about,' Clinton told a crowd inside a facility in Heinz field, where the Steelers play.

'Ask yourself, so if he's sitting across the table negotiating with people from those countries, is he going to put his own financial interests ahead of America's interests?'

'I can tell you this, when I'm sitting across the table from the Russians or anyone else, I know who I'm representing - the American people,' Clinton said.

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Clinton and Cuban were in Pittsburgh, Pennsylvania on Friday

Clinton and billionaire Mark Cuban (right), one of her most prominent backers, once again raised Donald Trump's ties to Russia

Cuban hit even harder in his own remarks, where he hammered Trump on the issue of trust.

Clinton and Cuban chatted casually inside the campaign plane

'There's gonna come a time where Donald Trump, God help, if he's president where [Vladimir] Putin or [Bashar] Assad would say to him, 'Donald if you do this, I'll give you $20 billion.'

'What's $20 billion to them?,' Cuban, the Dallas Mavericks owner and 'Shark Tank' cohost continued.

'What's $30 billion? To them it's nothing. If Donald Trump – who rips off people for thousands, gets offered by some dictator somewhere, some despot somewhere, $20 billion, you think he's gonna do what's best for the country or do you think he's gonna take the money?'

'Do you think he's got the temperament to do the right thing?' Cuban asked – prompting the crowd to yell out 'No!'

'Do you think he's got the fortitude to do the right thing? Do you think he cares more about you or his bank account? Can you trust Donald Trump? Absolutely not,' Cuban said.

Clinton made the stop to Pennsylvania with Cuban. The state that is part of her 'blue firewall' cutting off Trump's White House paths

The Democrat and the billionaire went in for a hug on Friday

Cuban described a U.S. under Trump as something like a developing country where bribery is commonplace.

'There's always a time in politics, global politics, where money's at stake. You hear all the stories about all these dictators who have taken billions, hundreds of billions of dollars and absconded with it.'

'And now look at islands they own – oligarchs who have taken from people billions and now live wherever they want,' he said.

Clinton made the stop to a state that is part of her 'blue firewall' cutting off Trump's White House paths. But the polls have tightened there, even as battleground New Hampshire has become all tied up.

Clinton was speaking inside a facility in Heinz field, Pittsburgh, where the Steelers play

Clinton was joined by Pro Football Hall of Famers and former Pittsburgh Steelers Mel Blount, left, and Franco Harris, right

She campaigned with Steeler legends Franco Harris and Mel Blount.

She also commented on the 'good news' employments numbers.

'That is 73 straight months of job growth,' Clinton said. 'And I believe that our economy is poised to really take off and thrive. But we need to make sure the economy is working for everyone not just those at the top.'

Clinton hailed Cuban at the top of her remarks, then invited him aboard her campaign plane as she flew to Detroit for yet another rally.

In an unexpected aside, Clinton said she feels 'sorry' for the press who cover all of her attempts to listen to Americans.

'I do feel kind of sorry for the press covering me – what are they going to say for the 100th time? "She was listening to people,"' Clinton said.