Giuliani reverses course, will not make trip to Ukraine in effort to hurt Biden, help Trump The president's personal attorney is targeting the 2020 Democratic frontrunner.

President Donald Trump's personal attorney Rudy Giuliani reversed course late Friday, saying he will no longer be traveling to Ukraine on a new mission to stop former Vice President Joe Biden from becoming the 2020 Democratic nominee.

Giuliani told Fox News' Shannon Bream in an interview, "I've decided, Shannon, I am not going to go to the Ukraine."

In the previously planned trip, Giuliani was to head to Ukraine where he wants to meet with that nation’s president-elect to encourage him to look into matters that could help his client, Trump.

“Explain to me why Biden shouldn’t be investigated,” Giuliani said earlier Friday in a tweet that went on to level allegations against the former vice president, who is now a leading Democratic candidate for president.

The former New York mayor has told reporters his agenda was to include a request to Ukrainian leaders for any information they can share about special counsel Robert Mueller’s probe, which concluded last month. He also plans to ask for more details about any action taken by Biden, while he was in office, that may have benefited his son, Hunter Biden.

Despite cancelling the trip, the president's lawyer did not rule out influencing the Ukrainian investigations in the future.

"I don't know, I'll play it by ear, I'll see what is going on," Giuliani told Bream. "I am actually quite confident that the facts, with regard to vice president -- former vice president -- Biden are so compelling that there's no way he gets from here to the election, without this being investigated, OK? And he would be better off getting investigated now, where it really isn't going to affect the election. It's 17 months away."

Giuliani predicted earlier Friday there would be questions about whether he was encouraging foreign interference in a U.S. presidential campaign, and he sought to preempt those concerns with comments first to the New York Times and later confirmed to ABC News.

"There’s nothing illegal about it,” Giuliani said. “Somebody could say it’s improper. And this isn’t foreign policy -- I’m asking them to do an investigation that they’re doing already and that other people are telling them to stop."

Giuliani also appeared on Fox News earlier in the day to further argue that the foreign trip is in keeping with his responsibility as Trump's attorney.

"I am his lawyer," Guiliani said on Fox. "One of the things lawyers do when they defend a client is develop innocent hypothesis explanations of what your client was charged with."

Giuliani’s decision to push for more information about the Biden family is part of an effort to bring attention to the work Hunter Biden did for a Ukrainian energy company at the same time his father was focusing on the country as part of his Obama White House portfolio.

The potential for conflicts between the public duties of elected officials and the private work of their relatives has been a familiar, and at times potent, focus of scrutiny in Washington in almost every administration.

Hunter Biden joined the board of the Ukrainian energy company Burisma Holdings during his father’s White House tenure. The hiring was controversial at the time. Hunter Biden had no known background in the country, but was said to be helping Ukraine gain energy independence from neighboring Russia.

The Ukrainian firm paid an investment and consulting partnership he ran called Rosemont Seneca roughly $3 million over a year and a half, according to 260 pages of Rosemont Seneca financial records disclosed in an unrelated court case and reviewed by ABC News.

The payments to Hunter Biden’s firm came at a time when his father was point person for the Obama administration on U.S. policy toward Ukraine and pushing hard for reforms in the country, which had been saddled with corruption allegations.

One element of that effort was the vice president’s push the dismissal of a Ukrainian prosecutor who had been accused of being soft on corruption. Biden described the effort -- in which said he used a planned announcement of a $1 billion U.S. loan guarantee to the country as leverage to fight corruption -- in a videotaped speech to the Council on Foreign Relations in January 2018, as first reported by The Hill.

“I said, ‘You’re not getting the billion.’ I’m going to be leaving here in, I think it was about six hours. I looked at them and said: ‘I’m leaving in six hours. If the prosecutor is not fired, you’re not getting the money,’” Biden said he told then-Ukrainian president Petro Poroshenko. “Well, son of a bitch, he got fired. And they put in place someone who was solid at the time.”

Giuliani has raised a concern that the prosecutor who was fired, Viktor Shokin, was at the time leading a corruption probe into Burisma Holdings, the firm that was paying Hunter Biden’s consulting partnership and on whose board he served. Whether the prosecutor was, in fact, looking into Burisma Holdings -- or if that effort was dormant -- has been in dispute, and like many politically-freighted matters in the Ukraine, the facts have now become difficult to reconstruct.

A spokesperson for the former vice president told The New York Times and later told ABC News that the 2016 push to oust Shokin came “without any regard for how it would or would not impact any business interests of his son, a private citizen” and was all part of a broadly-supported U.S. effort “to root out corruption in Ukraine.”

Hunter Biden told the newspaper in the statement, “At no time have I discussed with my father the company’s business, or my board service, including my initial decision to join the board.”

The Trump campaign, for its part, sought to distance itslef from the president's personal attorney, telling ABC News in a statement, "Rudy Giuliani is a private citizen. The campaign is not affiliated with these probes, and questions about them should be directed to him."

Trump told Politico, in an interview prior to Giuliani cancelling the trip, that he had not spoken to Giuliani "at any great length" about going to Ukraine.

But Giuliani, for one, was clear in his desire to tease out more on the controversy.

“I’m going to give them reasons why they shouldn’t stop it because that information will be very, very helpful to my client, and may turn out to be helpful to my government,” he said.

ABC News' Molly Nagle and Will Steakin contributed to this report.