(CNN) When Brazil's far-right President Jair Bolsonaro traveled to New York for the United Nations General Assembly in September, he was recovering from surgery and reportedly left after 30 hours without having met with any heads of state.

Despite the brevity of his trip, Bolsonaro did make time to meet with someone who occupies a special position within President Donald Trump's inner circle -- Rudy Giuliani.

The meeting, which involved a discussion of security and Brazil's prison system, according to a tweet by Bolsonaro's son who also attended, was just one in a series of interactions Giuliani has had with foreign leaders since he began representing Trump as his personal attorney last year.

Giuliani has met or communicated with senior government officials from at least seven foreign countries since he became Trump's pro-bono personal lawyer in April 2018 , according to a CNN review. He has also given paid speeches on behalf of an Iranian dissident group and met with a politician from the Dominican Republic.

While Giuliani has long dealt with foreign governments through the self-titled consulting firm he founded in 2002 after serving as New York's mayor, his more recent status as an attorney for the President has enabled him to interact with foreign leaders outside of official diplomatic channels while being treated like a US emissary.

Two current and two former State Department staffers told CNN that Giuliani's communication with foreign leaders has complicated, and at times undercut, official US foreign policy.

A current State Department staffer who spoke to CNN said US officials track some of Giuliani's comments because they carry the risk of confusing foreign entities and complicating messaging.

"When someone with that level of profile speaks on highly sensitive issues in a way that doesn't align with US policy, that is noted with concern," said the staffer, who spoke on the condition of anonymity due to the sensitivity of the issue.

Andrew Miller, a former official who worked in the State Department during the Bush and Obama administrations and served on the National Security Council during the Obama era said, "There are those in the State Department and the professional U.S. national security apparatus who view Giuliani as a shadow secretary of state."

In most of Giuliani's foreign interactions, he has pursued private business interests, but his association with Trump is often highlighted by state-run media and groups he meets with.

During a business trip to Bahrain in December 2018 in which Giuliani had a rare meeting with the country's leader, King Hamad bin Isa Al Khalifa, the state-run Bahrain News Agency described Giuliani as a "high-level US delegation."

Giuliani also met with Bahrain's crown prince and government ministers and discussed "the long-standing partnership between Bahrain and the U.S.," according to a statement on the prince's official website , which also referred to Giuliani as the leader of a US delegation.

Giuliani said at the time he traveled to Bahrain for talks related to his company Giuliani Security & Safety and the kingdom's security operation. Several months after his trip Giuliani confirmed that GSS had secured a contract to help train the kingdom's police force, which has received international criticism for its repression of protestors, especially in the wake of the 2011 Arab Spring. Giuliani has a previous tie to Bahrain. His former law firm Bracewell Giuliani worked on financial deals for the nation.

Giuliani's 2018 trip was arranged by the lobbying firm Sonoran Policy Group, which was paid by the Bahraini government to "facilitate meetings and interactions with U.S. administration officials," according to foreign lobbying. As a private attorney, Giuliani is not an official member of the President's administration.

Sonoran also hosted an event at The Hay-Adams hotel in Washington, DC, where Giuliani met with officials from the Democratic Republic of Congo and discussed a possible consulting arrangement in July 2018, according to a source familiar with the meeting. The New York Times first reported details of Giuliani's attendance at the event.

That event , the "Opportunity Africa Summit," sought to highlight "the strategic relationship between the U.S. and Africa," according to foreign lobbying disclosures.

CNN previously reported that criminal prosecutors and FBI counterintelligence agents have been looking into Giuliani's business dealings in Ukraine.

recurring theme in testimony given to House impeachment investigators examining allegations that Trump sought Ukrainian help to boost his reelection chances. Giuliani's efforts in that country have become arecurring theme in testimony given to House impeachment investigators examining allegations that Trump sought Ukrainian help to boost his reelection chances. Bill Taylor, the top US diplomat in Ukraine, said in closed-door testimony last month that Giuliani pressed Ukraine to "intervene in US domestic policy or politics" by opening investigations into Trump's political rivals. Giuliani has said he was solely acting "as a defense attorney to defend my client against false charges, that kept changing as one after another were disproven."

Giuliani's interactions with world leaders -- like his visit to Uruguay last November -- can be challenging for the State Department, because he does not work for the US government and does not have an obligation to report the contents of his conversations through official channels, according to Miller.

"It is dangerous because it creates the possibility that foreign countries can play various actors within the US off against each other," he said.

"When you have someone whose interests are not aligned with the US government who is prioritizing his private financial interests, that... makes it a possibility that there's going to be some compromising of US national security," Miller added.

Giuliani rejected the notion that he has enriched himself abroad through his associations with the President and said everything he has done is legal.

"I am in private law practice. I practice law honorably and well, never had a complaint. Never had an issue ever in 50 years of private law practice," Giuliani told CNN.

Giuliani has at times strayed from US policy in his statements during foreign dealings.

In June 2018, the US and 11 other nations issued a statement urging the government of Romania to continue its crackdown on corruption.

Less than two months later, Giuliani wrote a letter to Romania's President and criticized the country's National Anticorruption Directorate, which he said had "severely undermined" rule of law in the country. He called for "amnesty... to those who have been prosecuted and convicted" by the unit.

Former Vice President Joe Biden's son, Hunter, was previously retained by the same Romanian businessman but then referred the case to Freeh's firm, according to a source with knowledge. NBC first reported Hunter Biden's role in the case.

When Giuliani visited Armenia, where the nation's acting defense minister gave him a private briefing in October 2018, a reporter asked, "Mr. Giuliani as an adviser... should [the] Trump administration recognize the Armenian genocide?"

The US government does not formally recognize the mass killings of Armenians in the Ottoman Empire as genocide, but Giuliani responded, "I certainly recognize it and think it's a historical fact, but I'm not here in my capacity as a private lawyer for President Trump. I'm here as a private citizen."

Despite Giuliani's insistence on not representing the US government, the conference where he gave a speech referred to him in a schedule as "Advisor to the President of the United States on Cybersecurity," which was Giuliani's role before becoming a personal lawyer for Trump earlier that year.

Giuliani has also contrasted the US government's position on Iran in his work for the Mojahedin-e Khalq (MEK), an Iranian dissident group that the State Department designated a foreign terrorist organization until 2012

"In order to have peace and security in the Middle East, there has to be a major change in the theocratic dictatorship in Iran. It must end," Giuliani said, even though the Trump administration has called for a change in Iran's behavior, not regime change.

As Giuliani answered questions from reporters the day of the speech with his since-indicted associate Lev Parnas at his side, he clarified that the MEK paid him to give the speech in his private capacity.

Secretary of State Mike Pompeo downplayed Giuliani's actions when asked about them on Gray Television's "Full Court Press with Greta Van Susteren."

He said it wasn't "uncommon for private citizens to help" the US achieve its policy goals, but that he runs the State Department. "The ultimate responsibility falls to the United States government, for the secretary of state, to deliver on behalf of the outcomes President Trump has committed to the American people he'd achieve."

Giuliani's work on behalf of foreign groups has led some Democratic senators to call on the Justice Department to review whether Giuliani has complied with the Foreign Agents Registration Act, or FARA, which requires that representatives of foreign governments and political organizations file public documents that disclose their arrangements.

Sen. Tom Udall, a New Mexico Democrat who coauthored with six other Democratic senators a letter calling for a Justice Department review, told CNN in an interview he believes Giuliani could have violated FARA.

"He's advising the President. He is being paid by foreign entities, and that is exactly what's required to be disclosed under the Foreign Agent Registration Act," Udall said. "I think clearly there may be a violation of the law."

Fiona Hill, Trump's former top Russia adviser, testified in a deposition before three House committees in October that she was "extremely concerned that whatever it was that Mr. Giuliani was doing might not be legal," in regards to his work in Ukraine.

Hill also described learning of Giuliani's planned trip to Ukraine in May. "And there was, you know, kind of, quite a bit of consternation of the party of the State Department," she said.

Giuliani insists he is only guilty of one thing: defending the President.

When questioned by CNN's Drew Griffin about his international dealings, Giuliani responded, "I am being targeted by CNN because I am proving that you are corrupt in your coverage of the President all throughout this impeachment proceeding."