Hillary Clinton is convinced the Trump campaign worked directly with the Russian government to influence the 2016 election, telling an interviewer "it's pretty troubling."

In an interview with USA Today, Clinton — citing no direct evidence — said she believed President Trump's campaign communicated with the Russian government and had "an understanding of some sort."

"There certainly was communication and there certainly was an understanding of some sort," Clinton said. "Because there's no doubt in my mind that (Vladimir) Putin wanted me to lose and wanted Trump to win.

"And there's no doubt in my mind that there are a tangle of financial relationships between Trump and his operation with Russian money. And there's no doubt in my mind that the Trump campaign and other associates have worked really hard to hide their connections with Russians."

When asked if she thinks there was collusion between Trump and the Kremlin, Clinton said, "I'm convinced of it."

"I happen to believe in the rule of law and believe in evidence, so I'm not going to go off and make all kinds of outrageous claims," she continued. "But if you look at what we've learned since (the election), it's pretty troubling."

In the interview, Clinton doubled down on her criticisms of people she believed cost her the election, including former FBI Director James Comey.

She writes in her book, "What Happened," Comey "shivved" her and said it was a mistake not to push back harder against his late October letter about a new collection of emails.

"My first instinct was that my campaign should hit back hard and explain to the public that Comey had badly overstepped his bounds," she said. "My team raised concerns with that kind of confrontational approach. In the end, we decided it would be better to just let it go and try to move on. Looking back, that was a mistake."