President Trump said Friday that it would be “appropriate” for him to talk to Attorney General William Barr about opening an investigation into former vice president and 2020 Democratic presidential hopeful Joe Biden.

“Certainly it would be an appropriate thing to speak to him about, but I have not done that as of yet. ... It could be a very big situation,” Trump told Politico.

GIULIANI CANCELS UKRAINE TRIP, SAYS HE'D BE 'WALKING INTO A GROUP OF PEOPLE THAT ARE ENEMIES OF THE US'

Trump made his remarks after his personal attorney, Rudy Giuliani, said he would be traveling to Ukraine to urge the incoming Ukrainian government to look into several probes that may prove "very, very helpful" to the Trump White House as it looks to prove it was Democrats who improperly conspired with foreign governments, not the Trump campaign.

One of those investigations pertains to allegations that Biden pressured Ukraine to fire its top prosecutor in order to take the heat off the prosecutor's probe into a company that employed his son, Hunter, as a board member.

Another such investigation concerns evidence that the Democratic National Committee (DNC) and Hillary Clinton campaign may have worked with Ukrainians to illegally help Clinton by revealing damaging information about then-Trump campaign chairman Paul Manafort.

However, Giuliani said Friday evening on "Fox News @ Night" that he will not be traveling as planned, saying he believed he would be "walking into a group of people that are enemies of the president, and in some cases, enemies of the United States and in one case, an already convicted person who has been found to be involved in assisting the Democrats with the 2016 investigation.”

Giuliani said his decisions had nothing to do with the 2020 election, but Giuliani had faced fierce pushback from Democrats, who accused the president of "asking a foreign government to investigate his political rival."

On Friday, Trump told Politico that the only reason the Biden controversy wasn’t a full-blown scandal yet is that Biden is a Democrat.

“Because he’s a Democrat,” Trump said, the revelations had about “one-hundredth” the impact as it would have if Biden “were a Republican.”

CLINTON-UKRAINE COLLUSION ALLEGATIONS 'BIG' AND 'INCREDIBLE,' WILL BE REVIEWED, TRUMP SAYS

It isn’t the first time Trump has weighed in on the controversies linking Democrats to Ukraine. Asked last month by Fox News host Sean Hannity whether Americans need to see the results of Ukraine's ongoing investigation into whether officials in that country worked with the Clinton team, Trump replied, "I think we do."

"It sounds like big stuff, very interesting with Ukraine,” he said.

But any push from Trump to get the Justice Department to investigate political opponents is likely to face intense resistance from Democrats.

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Sen. Kamala Harris, D-Calif., last week sent a letter to the Department of Justice’s inspector general demanding he investigates whether the White House had urged Barr to investigate President Trump’s political opponents -- after Barr appeared to demur on the question somewhat in congressional testimony.

“In response to my questions during the [Senate Judiciary] hearing, Attorney General Barr proved unable or unwilling to state whether he had been directed to open investigations at the request or suggestion of the President or other White House officials -- an alarming response that strikes at the very heart of the rule of law and threatens to undermine the longstanding independence of the Justice Department,” she said in a letter to Inspector General Michael Horowitz.

Fox News’ Gregg Re and Charles Creitz contributed to this report.