Turkish President Recep Tayyip Erdogan, Iranian President Hassan Rouhani and Qatari Emir Tamim bin Hamad Al Thani are scheduled to deliver keynote addresses on Thursday.
The Kuala Lumpur summit will formally begin on Thursday morning in the Malaysian capital to deliberate upon issues faced by the Muslim world.
Malaysian Prime Minister Mahathir Mohamad, Turkish President Recep Tayyip Erdogan, Iranian President Hassan Rouhani and Qatari Emir Tamim bin Hamad Al Thani are the top leaders participating in the event.
Pakistan leader Imran Khan was originally slated to attend, but withdrew this week in a move seen to assuage its ally, Saudi Arabia.
Khan held a telephone discussion with the Malaysian prime minister "to inform of his inability to attend the summit, where the Pakistani leader was expected to speak and share his thoughts on the state of affairs of the Islamic world", according to Malaysian prime ministry.
Pakistan's Foreign Minister Shah Mahmood Qureshi said Saudi Arabia and the UAE concerns the summit could cause a "division in ummah", Dawn reported.
Saudi Arabia said the summit was the "wrong forum" for matters of importance to the world's 1.75 billion Muslims, though some analysts suspected the kingdom feared being diplomatically isolated by regional rivals Iran, Qatar and Turkey.
Mahathir also held a video conference with Saudi King Salman bin Abdulaziz to allay concerns that the summit was aimed to replace any existing Muslim body.
"The summit, which is into its fifth edition, is a non-governmental organisation initiative supported by the Malaysian government and is not intended to create a new bloc as alluded to by some of its critics. In addition, the summit is not a platform to discuss religion or religious affairs, but specifically to address the state of affairs of the Muslim Ummah," Mahathir's office said in a statement.
The summit will deliberate on issues and find new and workable solutions to problems afflicting the Muslim world and seek to revive the Islamic civilisation, the organisers said. The issues which are expected to dominate the summit include governance, human resource development, corruption and Islamophobia.
The four-day summit could also address mounting outrage over China's camps for Uighur Muslims in Xinjiang Uighur Autonomous Region – a subject that will doubtless upset Beijing.
“We have always reflected on how great, enriching and powerful the Islamic civilisation was. It is a chapter in history and we yearn for its return. It will remain a yearning unless we do something about it,” said Mahathir, who is also chairman of the summit, in a video message.
Indonesia, with the world's largest Muslim population, was represented by Vice President Maruf Amin, a cleric overseeing the country's fight against radicalisation and terrorism.
Ahmad Azam Ab Rahman, a participant of the summit, said that “the KL summit will try to create a model ... in the economy, media or development ... at a smaller level, which, if successful, can be expanded to a mass level thereafter.”
Rahman, who leads Malaysia-based Global Peace Mission, said that the participants will be deliberating on the issue of sovereignty, development and “how Muslims must work together”.
Turkey-based political analyst Ibrahim Karatas said the summit provides a good opportunity where Muslim states can boost their cooperation.
“Turkey and Malaysia are brother countries ... they must particularly collaborate on big projects. Turkey is developing indigenous weapons. Malaysia can be a partner to them and likewise other [participating] countries,” he said.
Mahathir, Erdogan, Rouhani and al Thani are scheduled to deliver keynote addresses on Thursday.