As President Donald Trump finds himself engulfed in a burgeoning political scandal over his actions toward Ukraine, his personal attorney Rudy Giuliani claimed Sunday that if the president did not ask that country to investigate former Vice President Joe Biden, it would have violated the Constitution.

Trump "called them up and he said, 'I want you to investigate these charges of corruption,'" Giuliani told ABC's "This Week." "If he hadn't asked them to investigate Biden, he would have violated the Article II, Section 3 of the Constitution."

That portion of the Constitution includes a line stating the president "shall take care that the laws be faithfully executed."

Giuliani took to the Sunday political talk shows to defend his client amid a burgeoning political scandal surrounding Trump's actions toward Ukraine, including a July 25 phone call with Ukrainian President Volodymyr Zelenskiy in which Trump asked his Ukrainian counterpart to investigate the Biden family. Biden's son, Hunter, sat on the board of a Ukrainian natural gas company that had previously been under investigation by that country's former top prosecutor.

The matter is now the subject of a formal impeachment inquiry launched by the House last week.

Giuliani, the former mayor of New York City, hit the morning shows after a whistleblower complaint at the center of the scandal was made public Thursday detailing how White House officials were so concerned about what the president said in a July call with Zelenskiy that they intervened to "lock down" the record of the conversation.

Download the NBC News app for full coverage of the impeachment inquiry

The whistleblower, whose name and gender have not been released, lodged the formal complaint out of a belief that Trump was "using the power of his office to solicit interference from a foreign country" in the 2020 election. The whistleblower relied on the accounts of White House and other U.S. officials in the complaint.

The White House released a summary of the president's discussion with Zelenskiy on Wednesday, which showed Trump asked the Ukrainian president to look into why that country's top prosecutor apparently had ended an investigation of the gas company, whose board at the time included Biden's son. At another point in the call, Trump appeared to ask Zelenskiy about the debunked "CrowdStrike" conspiracy which distances Russia from culpability in the hacking of Democratic National Committee emails.

CrowdStrike is a cybersecurity firm that investigated the hacking of Democratic National Committee email servers during the 2016 election, and the conspiracy theory paints its findings about Russia's hacking efforts as suspect and politically motivated.

Earlier on "This Week," Trump's former homeland security adviser, Tom Bossert, said the "CrowdStrike" theory had been "debunked" and criticized Giuliani for pushing the theory with the president. Giuliani responded, saying Bossert didn't know what he was talking about and that the attorney "never peddled" the theory to Trump.

"I have never engaged in any theory that the Ukrainians did the hacking," Giuliani said. "In fact, when this was first presented to me, I pretty clearly understood the Ukrainians didn't do the hacking, but that doesn't mean Ukraine didn't do anything."

Speaking with CBS's "Face the Nation," Giuliani said Secretary of State Mike Pompeo was "aware" of his efforts in Ukraine, saying he even received a thank you from the State Department "for doing a good job."

Giuliani said he spoke with Pompeo last week about his Ukrainian efforts and Pompeo said, "'Yes, I know about this.'"

Regarding Biden, Giuliani for months has pushed for Ukraine to further investigate the former vice president, one of the leading 2020 Democratic contenders — an effort assisted by the State Department. Giuliani's allegations of impropriety stem from Biden's 2016 call — widely backed by the international community — for Ukraine to crack down on corruption, including removing a Ukrainian prosecutor, Viktor Shokin, who was seen as ineffective and was later removed by the country's parliament. One of the cases that Shokin was investigating involved Burisma Holdings.

However, earlier this year, Bloomberg News, citing documents and an interview with a former Ukrainian official, reported the Burisma investigation had been dormant for more than a year by the time Biden called for the crackdown on corruption. The then-Ukrainian prosecutor general, Yuriy Lutsenko, told the news agency that he found no evidence of wrongdoing by Biden and his son. PolitiFact, meanwhile, reported that it found no evidence to "support the idea that Joe Biden advocated with his son's interests in mind."

Meanwhile, members of the European Union and International Monetary Fund have said Biden was justified in pushing for Shokin's removal.

Full coverage: Trump impeachment inquiry

And, as "Face the Nation" highlighted, Lutsenko said he found "nothing" under Ukrainian law implicating the Bidens of wrongdoing. In the summary of the July phone call with Zelenskiy, Trump referred to Lutsenko as a "very good prosecutor" who was "treated very badly," The New York Times reported. Lutsenko, who met and spoke with Giuliani multiple times over the past year, stepped down from office last month.

In response, Giuliani said Lutsenko was "exactly the prosecutor that Joe Biden put in in order to tank the case," accusing the media of being "so blinded" to the Biden allegations because he's a Democrat.

A Biden campaign source said to NBC News about Giuliani's comments, "This charade has gotten so sad and deflated that at this point we just feel sorry for the guy."

When "This Week," host George Stephanopoulos pointed to international and U.S. leaders saying Shokin was corrupt, Giuliani responded, "Oh, they all said it. Anybody prove it?"