Speculation is mounting as to whether Iran's new supreme leader is finally ready to show his face, as Ayatollah Khamenei's body arrives at Tehran's Grand Mosalla ahead of a days-long funeral.Millions of people and a coterie of foreign dignitaries were expected to attend Saturday's official ceremony for Ali Khamenei, with Tehran's chief negotiator calling for a massive turnout to avenge his death.Khamenei was killed in the US-Israeli strikes that triggered the Middle East war on February 28, with his son, Mojtaba, succeeding him.Mojtaba has not been seen in public since becoming supreme leader, however, and it remains unknown as to whether he will be present at the main ceremony in Tehran. Photos showed mourners carrying Khamenei's coffin, emblazoned with Iran's tricolour flag, into the Grand Mosalla, one of the Islamic republic's most important ceremonial venues.Others show crowds at a pre-funeral ceremony clad in black, as the coffin is set down against a backdrop of red flowers and white butterflies hanging in the air.Preparations for Khamenei's public funeral, initially delayed at the height of the war, are taking place as Iran and the United States observe a fragile ceasefire after signing a preliminary deal to halt the conflict.Pakistan, a key mediator in the US-Iran talks, said its Prime Minister Shehbaz Sharif would attend the ceremony. Religious leaders pay their respects beside the coffin of late Iranian Supreme Leader Ayatollah Ali Khamenei and other coffins before his state funeral at the Imam Khomeini Hussainiyah in Tehran, Iran, July 3 Millions of people and a coterie of foreign dignitaries were expected to attend Saturday's official ceremony for Ali Khamenei, with Tehran's chief negotiator calling for a massive turnout to avenge his death A portrait of the slain Iranian Supreme Leader Ayatollah Ali Khamenei hangs at the Imam Khomeini Mosalla Grand Mosque as preparations are underway ahead of his dayslong funeral ceremonies in Tehran, Iran, Friday, July 3China, Afghanistan and Iran's neighbours in the Caucasus region said they would also be sending representatives.Workers were readying the Grand Mosalla on Thursday, while security teams stopped passing cars and curious bystanders looked on.'We are planting flowers and watering the shrubs for the farewell ceremony of our martyred guide,' said worker Hossein Moghadassi, clad in a hat and a scarf to cover his face as the temperature soared.'People will come from all over Iran. There will be huge crowds.'Tehran's chief negotiator Mohammad Bagher Ghalibaf had called on Thursday for 'all the Iranian people...to write a glorious page in the history of Islamic Iran through your presence'.'The nation's call for vengeance must ring in the ears of the whole world,' Ghalibaf, who is also Iran's parliament speaker, added in a statement.Khamenei, a spiritual figure for many Shias, was killed at the age of 86 in strikes on his compound in the centre of the Iranian capital.He will lie in state for three days at the colossal Grand Mosalla, which has been draped in banners featuring images and quotes of Khamenei. Khamenei was killed in the US-Israeli strikes that triggered the Middle East war on February 28, with his son, Mojtaba, succeeding him China, Afghanistan and Iran's neighbours in the Caucasus region said they would also be sending representatives Mourners carry the coffin of Iran's slain supreme leader Ali Khamenei at the Grand Mosalla in Tehran on July 3 The ceremonies are expected to draw between 15 and 20 million mourners, according to officials, which would make it the biggest state funeral in the country's history Mourners offer prayers beside the coffin of Zahra Haddad Adel, wife of Iran's supreme leader Mojtaba Khamenei, during her funeral in Tehran on July 2The bodies of his slain relatives will also be presented.The ceremonies are expected to draw between 15 and 20 million mourners, according to officials, which would make it the biggest state funeral in the country's history.Ghalibaf called it 'one of the most significant moments' in Iran's history.Tehran, as well as the holy cities of Qom and Mashhad, which will host later stages of the funeral and burial ceremonies, will observe public holidays while the events are underway.Authorities have ordered public and private offices in Tehran to close from Saturday through Monday, while traffic restrictions will make much of the city centre inaccessible to private vehicles.The airspace over Tehran will be partially closed from Friday and fully closed on Monday.Following the ceremonies in Tehran, Khamenei's body will be taken to the Iraqi holy cities of Najaf and Karbala before his burial on July 9 at the shrine of Imam Reza in the northeastern Iranian city of Mashhad, his birthplace.Representatives from around 30 countries are expected to attend the funeral, with people pouring in from neighbouring Iraq, Afghanistan and Pakistan. An exterior view of the Imam Khomeini Mosalla Grand Mosque, ahead of farewell and funeral ceremonies for late Iranian Supreme Leader Ayatollah Ali Khamenei, in Tehran, Iran, July 3Mohsen Sazegara occupied several senior positions in the early Islamic Republic before becoming disillusioned with the revolutionary government and leaving it in 1989.Speaking to the Daily Mail from Washington, DC, he said 'nobody knows' whether Mojtaba is still alive, but whether he appears at his father's funeral will be a good indication.'If Mojtaba doesn't show, then I can say that maybe he is dead, or maybe he's in a situation of poor health, where he can't stand or talk.'He said the new supreme leader might be in a coma, or missing limbs, making a public appearance difficult.'It's historic tradition,' Sazegara said, regarding the funeral. 'Mojtaba should be in public next week. If not, then maybe he's dead.'Workers applied fresh paint across the venue, while a heavy police presence could be seen around the site. Footage aired by state television showed workers welding metal structures as cranes lifted construction materials around the complex.With huge crowds expected, state television has been urging mourners to use public transport to reach the venue and issued public safety messages urging people to stay hydrated, as temperatures are set to rise during the funeral period.State television has also devoted much of its programming in recent days to documentaries on Khamenei's life.A separate event for foreign heads of state is scheduled for Friday, according to Ali-Akbar Pourjamshidian, secretary of the funeral ceremony headquarters.Foreign ministry spokesman Esmaeil Baqaei, speaking on state television, said 'we have not extended an official invitation to Europe'.He accused European nations of standing 'on the wrong side of history' and called their position on the US-Israeli war 'truly disgraceful'.Iran has meanwhile maintained its close ties with its ally Russia throughout the war.The ceremony also comes six months after nationwide protests that began over the rising cost of living before evolving into anti-government demonstrations.Across Tehran, funeral posters promised Iran a 'bright future', while others displayed the ceremony's slogan: 'We Must Rise.''The issue of the Supreme Leader's attendance is not within my authority or knowledge,' said Pourjamshidian, regarding whether Khamenei's son and successor Mojtaba will be present.'If there is any programme, it will certainly be announced by the Office of the Leader of the Islamic Revolution.'