Iranian president Ebrahim Raisi, who died in a helicopter crash at the weekend, is to be buried in his home city of Mashhad on Thursday.
Raisi is to be laid to rest at the city’s shrine of Imam Reza, the eighth imam of Shia Islam.
High-ranking representatives of friendly states are expected to attend, including Russian parliamentary leader Vyacheslav Volodin.
Iran’s state railway company has organised special trains to take mourners from Tehran to the north-eastern city.
There have been several ceremonies and public displays of mourning for Raisi, late foreign minister Hossein Amirabdollahian and other victims of Sunday’s crash.
Millions of mourners flocked to a funeral procession in Tehran on Wednesday.
Raisi and Amirabdollahian were killed in the crash with seven other occupants of the ill-fated helicopter.
They went down in dense cloud in the mountains while travelling back from a meeting with Ilham Aliyev, the president of Azerbaijan.
Iran’s religious leader, Ayatollah Ali Khamenei, ordered five days of national mourning, and a nationwide holiday was held on Wednesday.
Raisi’s death has provoked mixed reactions in Iran.
While supporters of the country’s Islamic regime have mourned the loss of an important political figure, critics have highlighted the heightened repression his administration oversaw.