Russian Presidential Press Secretary Dmitry Peskov said State Duma Speaker Vyacheslav Volodin will participate in the farewell ceremony for Iranian President Ebrahim Raisi, Interfax reported on May 21. 

"Our Iranian friends have scheduled a farewell ceremony for tomorrow, and therefore, the Russian side will be represented by a delegation led by Volodin." he said, adding, "He’s going there [Iran] tomorrow," the Kremlin speaker said.

Raisi and the country's Foreign Minister Hossein Amir-Abdollahian, along with other officials, were found dead on May 20, several hours after their helicopter crashed in fog in a mountainous area, with Iranian authorities yet to provide any cause for the incident. Thousands of people marched through the streets of the northwestern Iranian city of Tabriz on May 21 as part of the funeral procession for President Ebrahim Raisi and seven members of his entourage after they were killed in a helicopter crash.

Earlier, it was reported that the Russian president intended to travel with strict security measures and an escort of four Sukhoi-35 planes, Russian media channels reported. However, that was later denied by the Kremlin in a flurry of conflicting reports out of Moscow.

Following the disappearance of Raisi's helicopter on May 19, the Kremlin was quick to respond with offers of support and cooperation with its growing ally, Iran. 

“Sayyid Ebrahim Raisi was an outstanding politician whose whole life was devoted to serving [his] country,” read a statement published on the Kremlin’s website on May 20.

“As a true friend of Russia, he made an invaluable personal contribution to the development of good-neighbourly relations between our countries and made great efforts to bring them to the level of strategic partnership,” the statement continued.

The stringent security measures for Putin's trip indicate that Russia further suggests that the helicopter incident was not an accident and has offered to investigate the crash.

Earlier, Russian Secretary of the Security Council Sergei Shoigu, in a Telegram message to his Iranian counterpart, announced Russia’s readiness to help Iran find the “true” reasons behind the crash of the President’s helicopter, which suggests that the country believes that it was not an accident, Tass reported.

The official Iranian government line is bad weather with heavy fog caused the helicopter carrying President Raisi and his delegation to crash between Varzaqan and Jolfa in East Azerbaijan Province.

The helicopter was carrying Raisi, Amir-Abdollahian, East Azarbaijan Governor Malek Rahmati, Friday Prayers leader of the city of Tabriz Mohammad Ali Al-e Hashem, and a member of the president’s bodyguard team, Mahdi Mousavi. The helicopter’s pilot, co-pilot, and crew were also on board.

The temporary leadership of Mohammad Mokhber has not suggested foul play in the death of the president and other top officials; however, comments inside Iran and outside are starting to shift from shock to accusations of a potential hit on the leadership in some cases.

Raisi and his delegation were returning from a ceremony to open a dam on the Aras River with Azerbaijan’s President Ilham Aliyev in a sign of warming relations between the two neighbours.

Following the crash, Iran's Ambassador to Russia, Kazem Jalali, was called to the Kremlin for an emergency meeting with Putin; not much is known about that meeting, which was likely to inform the Russians about the incident.