Giuliani: Biden not 'smart enough' to be president

President TrumpDonald John TrumpSchiff pleads to Senate GOP: 'Right matters. And the truth matters.' Anita Hill to Iowa crowd: 'Statute of limitations' for Biden apology is 'up' Sen. Van Hollen releases documents from GAO investigation MORE’s personal attorney Rudy GiulianiRudy GiulianiSchiff pleads to Senate GOP: 'Right matters. And the truth matters.' Schiff tells Senate Ukraine interference conspiracy was 'brought to you by the Kremlin' The Hill's Morning Report - House prosecutes Trump as 'lawless,' 'corrupt' MORE said he doesn’t think former Vice President and current 2020 frontrunner Joe BidenJoe BidenSchiff pleads to Senate GOP: 'Right matters. And the truth matters.' Anita Hill to Iowa crowd: 'Statute of limitations' for Biden apology is 'up' Sen. Van Hollen releases documents from GAO investigation MORE is capable of being president because he's not "smart enough." 

“I don’t think the guy’s smart enough to be president of the United States,” Giuliani told Hill.TV during an interview that aired on Monday. “I’ve known Joe for a long time.”

The former New York City mayor also doubled down on calls for the Biden family to be investigated. He cited some business dealings by Biden's son, Hunter Biden, that took place in China and Ukraine when his father was still vice president. 

“I also think his activities in Ukraine and China should be seriously investigated,” Giuliani told Hill.TV. “It’s a Democratic press that’s protecting him and they’re actually going easy on him.”

The Biden campaign declined Hill.TV’s request for comment.

Trump allies and conservatives have long claimed that the Biden's have been involved corrupt business dealings. Earlier this year, conservative author Peter Schweizer claimed that Hunter Biden inked a deal with the Chinese government in 2013, just days after then-Vice president Joe Biden visited the country. 

Their concerns also center around whether Joe Biden demanded the resignation of former Prosecutor General Viktor Shokin when Shokin was investigating Burisma, where Hunter Biden was a board member at the time. But Ukraine’s top prosecutor said in May that he found no evidence of wrongdoing.

Both Biden and his son have also shot down the accusations. In an interview with ABC News earlier this month, Hunter Biden directly addressed some of allegations, calling them “demonstrably false," and said they were narratives that have been created by "the right-wing political apparatus."

However, Giuliani said that he hasn’t ruled out a trip to Ukraine to meet with the country’s leaders and ask them to pursue an investigation. 

In May, Giuliani announced and then subsequently cancelled plans to travel to Ukraine to ask the Ukrainian government to look into the origins of special counsel Robert MuellerRobert (Bob) Swan MuellerSchiff: Trump acquittal in Senate trial would not signal a 'failure' Jeffries blasts Trump for attack on Thunberg at impeachment hearing Live coverage: House Judiciary to vote on impeachment after surprise delay MORE’s Russia probe and Biden’s past influence in the country.

“I could — I like the Ukraine,” he told Hill.TV. “I think the Ukraine is a great country, I think it is riddled with corruption.”

Giuliani’s comments come amid reports that he helped establish a backchannel with top Ukrainian officials.

Buzzfeed News reported Monday that two U.S. operatives reporting to Giuliani met with Ukrainian officials in an attempt to gather information to use in the 2020 presidential election. They also reportedly sought to push Ukrainian prosecutors to investigate Biden. 

Story updated at 5:00 P.M. EST.

—Tess Bonn