Vice President Mike Pence said Thursday that he believes it’s time for Special Counsel Robert Mueller to finish his investigation of Russian interference in the 2016 election and other potential misdeeds by people in President Donald Trump's orbit.

'In the interests of the country, I think it’s time to wrap it up,' Pence told NBC News in an airplane hangar following the return home of three Americans who had been held prisoner by North Korea.

Pence said the Trump administration has 'fully cooperated' with Mueller’s probe, including turning over more than 1 million documents. But he wouldn't respond to a question about whether he agrees with the president that the entire case is a 'hoax.'

Trump has called the investigation a 'witch hunt'; his outside counsel, former New York City Mayor Rudy Giuliani, has called on the Justice Department to put an end to the probe.

'I would very respectfully encourage the special counsel and his team to bring their work to completion,' Pence added Thursday.

Vice President Mike Pence said Thursday that it's time for Special Counsel Robert Mueller to be done with his year-long investigation into Russia's election meddling in 2016

Mueller has reportedly gone far afield from his original mandate, probing business relationships of the Trump family and the work of his personal attorney in a hush-money case involving a pornographic actress

President Donald Trump, shown in the wee hours of Thursday morning greeting three former prisoners back to the U.S. from North Korea, could be facing a subpoena from Mueller – and a lengthy legal struggle to try and quash it

The vice president was pressed on the news about millions of dollars in payments from companies to Trump’s personal attorney Michael Cohen. Pence said that was a 'private matter' and 'something I don’t have any knowledge about.'

Cohen, Trump’s self-described longtime 'fixer' is also under investigation for his role in paying hush money to a porn star in the days leading up to the 2016 presidential election.

The adult film actress, whose stage name is Stormy Daniels, says she had a torrid affair with Trump in 2006 and 2007, just after future first lady Melania Trump gave birth to their son Barron.

Hanging heavy over the Mueller probe is the possibility that Trump himself could face a subpoena if he listens to his his lawyers' advice and refuses a formal interview with the special counsel.

But Trump fears Mueller's operation is biased against him: 'We have 13 people and they’re all Democrats – real Democrats. Angry Democrats'

Pence said: 'I would very respectfully encourage the special counsel and his team to bring their work to completion'

Trump attorney Rudy Giuliani says the president could plead the Fifth Amendment and refuse to answer questions – if the White House were to lose an inevitable court challenge to the subpoena's legality.

It is longstanding Justice Department policy that a president can't be criminally indicted. That puts Mueller in the position of having to explain the point of forcing Trump to give Grand Jury testimony.

Mueller could grant him immunity from criminal prosecution, a situation that could compel Trump to testify under oath – potentially saying things that could be used against him in an impeachment proceeding.

Such a situation would draw a new round of legal challenges since impeachment is reserved exclusively for Congress – and Mueller, as a Justice Department employee, works for the Executive Branch of the federal government.

Last week on ABC, Giuliani said he can't be 'confident' Trump would not refuse to answer questions on the his absolute Fifth Amendment right to avoid incriminating himself.

Trump told DailyMail.com as he left the White House last Friday that he would only let Mueller interview him if he thought he could get a fair shake

Rudy Giuliani said recently that Trump could plead the Fifth Amendment if Mueller subpoenas him

'How can I ever be confident of that?' Giuliani asked. 'I've got a client who wants to testify... I hope we get a chance to tell him the risk that he's taking.' panel that previously investigated allegations of Russian collusion with Trump's 2016 campaign organization, slapped down Giuliani's claim.

'He is going to need to comply with a subpoena. If they take that case to court, they are going to lose,' Schiff said.

President Trump said Friday that he is still willing to talk directly with Mueller but worries that the deck would be stacked against him.

He said his his legal team is counseling him against giving Mueller the chance to quiz him about his campaign's links to the Kremlin, and about claims that he obstructed justice in 2017 by firing then-FBI Director James Comey.

'I would love to speak, but I have to find that we're going to be treated fairly,' Trump said at the White House. 'I would love to speak because we've done nothing wrong.'