(CNN)-- Iranian President Masoud Pezeshkian sent separate messages on Thursday to a number of world leaders, expressing his gratitude and appreciation for their participation in the funeral procession of former Supreme Leader Ali Khamenei.

The messages sent by Pezeshkian included leaders from Pakistan, Tajikistan, Armenia, Georgia, and the National Leader of Turkmenistan, according to Iran's official IRNA news agency.

Pezeshkian thanked Pakistani Prime Minister Shehbaz Sharif and praised his participation and that of the Pakistani delegation in the funeral ceremony, emphasizing that 'the Iranian people will never forget Pakistan's government and people's solidarity and support,' according to IRNA.

In his message to the President of Tajikistan, Pezeshkian expressed gratitude for his attendance at Khamenei's farewell ceremony and his heartfelt condolences to the Iranian people, stating that it 'will remain etched in the historical memory of relations between the two countries.'

In his message to Georgian President Mikheil Kavelashvili, Pezeshkian thanked him for attending and for the condolences of the Georgian people and government with the Iranian people, stating that it 'will remain immortal in the historical memory of relations between the two peoples that span three thousand years.'

Meanwhile, massive crowds gathered in the Iranian city of Mashhad, walking along the route of Khamenei's funeral procession ahead of his burial ceremony.

Iranian media reported that the vehicle carrying Khamenei's body and several family members had not yet arrived.

Nevertheless, the crowds of mourners headed toward the shrine of Imam Reza, where the late leader will be laid to rest, with many waving red flags as a call for revenge for the killing of their leader.