WASHINGTON - Rudy Giuliani, whose actions as President Donald Trump's personal lawyer have helped set in motion an impeachment inquiry, abruptly canceled his scheduled paid appearance at a Kremlin-backed conference in Armenia next week.

Giuliani, who confirmed to The Washington Post on Friday morning that he would attend the event, reversed himself that evening after The Post reported on his participation in the meeting, which Russian President Vladimir Putin and other top Russian officials are expected to attend.

The two-day conference is sponsored by Russia and the Moscow-based Eurasian Economic Union, a trade alliance launched by Putin in 2014 as a counterweight to the European Union.

According to an agenda for the event posted online, Giuliani was set to participate in a panel led by Sergey Glazyev, a longtime Putin adviser who has been under U.S. sanctions since Russia's invasion of Ukraine five years ago.

Giuliani said Friday evening that he was no longer planning to attend the meeting. "I didn't know Putin was going," he said in a brief interview, adding in a text: "Discretion is the better part of valor."

Giuliani's decision to take part in the conference astounded national security experts. His appearance would have come days after the release of a whistleblower complaint accusing Trump and Giuliani of pressuring Ukrainian officials for damaging information about Democrats.

Trump this summer withheld military aid from Ukraine, which counts on U.S. support to help fend off pro-Moscow separatists in the country's eastern provinces. As part of his efforts in Ukraine, Giuliani has said the focus on Russia's interference in the 2016 election has overlooked what he claims was meddling by Kiev.

The agenda for the Eurasian conference showed Giuliani was the only American scheduled to speak at the gathering.

In an interview Friday before canceling his plans, Giuliani angrily rejected questions about whether it would be appropriate for him to attend the event at which he also appeared last year.

"I will try to not knowingly talk to a Russian until this is all over," he retorted.

The former New York mayor confirmed in the interview that he intended to accept payment for his appearance but declined to say how much he would receive or which group or person was going to pay him.

"It goes to my company," Giuliani said.

The White House and State Department declined to comment.

Current and former White House aides said there is internal exasperation with Giuliani's behavior and the fact that he does not clear his media appearances or paid speeches with the administration. Giuliani has said he works for the president in a personal capacity and does not take a salary from the government or the president.

A spokesman for the Eurasian conference declined to comment on Giuliani but said Putin, Iranian President Hassan Rouhani and Singaporean Prime Minister Lee Hsien Loong are set to attend the conference in the Armenian capital of Yerevan on Tuesday.

The conference is a regular summit of the Eurasian Economic Union, an economic trading union whose members are Armenia, Belarus, Kazakhstan, Kyrgyzstan and Russia.

It is the brainchild of Putin and was created in response to democratic upheavals taking place at the time in former Soviet countries. Putin has aimed to use the group to establish Russia as a bulwark against Europe and a center of gravity in the former Soviet region, describing the EEU as "a new supranational union that could become one of the poles of the modern world."

In 2012, then-Secretary of State Hillary Clinton called the group part of an effort to "re-Sovietize the region."

National security experts said Giuliani's presence at the event could have bolstered the E.U. rival.

David Kramer, a former State Department official responsible for Russia and Ukraine during the George W. Bush administration, called it "terrible judgment" for Giuliani to have agreed to attend, saying his participation would have lent "credibility to an organization Putin set up as an alternative to the European Union."

Michael McFaul, who served as U.S. ambassador to Russia in the Obama administration, said he was surprised Giuliani would agree to attend the Eurasian conference, particularly since the organization was a flash point in Russian-Ukrainian tensions. He noted it was created by Putin at a time when Ukraine was considering joining the European Union.

"I can't remember anything like this," McFaul said. He said Giuliani, as a private citizen, has a right to speak to any organization but called the conference an "odd" choice.

An agenda of the two-day summit says it is focused on transit in the region. The agenda, which was posted online in English, states clearly that Putin is set to take part in the official closing ceremony on Tuesday with Rouhani and leaders of the EEU's other member countries.

Giuliani wrote in a text Friday evening that the event "wasn't that important."

"I don't need to give the Swamp press more distractions," he added.

Giuliani had been scheduled to appear on a panel titled "Digital financial technologies - new opportunities for integrating payment systems of the Eurasian continent in transport logistics."

The moderator listed on the agenda is Glazyev, an economist who served as one of Putin's top advisers until this August and who is viewed in Moscow's diplomatic circles as a possible successor to him. Next week, he is expected to be appointed to a top post at the commission that oversees the EEU.

Glazyev was one of a number of senior Russian government officials sanctioned by the Obama administration in 2014 as punishment for Russia's incursion into Crimea.

Last year, Giuliani was also listed as a participant in a panel moderated by Glazyev. In a photo posted online by the group, Giuliani can be seen standing at a lectern to the left of a group of seated men that include Glazyev.

Giuliani told The Post on Thursday that he did not realize Glazyev would be present at last year's meeting before attending.

"When we found out he was on the panel, the head of my security detail said [to the organizers], 'The mayor is just going to be giving a speech and leaving, and if you don't like that, screw you,' " Giuliani said.

Giuliani said he could not remember whether he and Glazyev spoke at the event.

"I was discussing Russian collusion," he said, sarcastically. "He helped me tank the case. Do you know what an idiot you sound like right now?"

"What does it matter what I did at the conference?" Giuliani added.

Before backing out of the event, Giuliani said that he was unaware his panel at next week's conference was again scheduled to feature Glazyev.

In interviews this week, Giuliani has rejected any scrutiny of his conduct, saying attention instead should be put on his claims about former vice president Joe Biden and the Democrats.

"I'm not an idiot. I know you all are going after me. I know what you guys are doing with this," he said.

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Ferris-Rotman reported from Moscow. The Washington Post’s Carol Morello contributed to this report.