The Hajj agreement comes amid continuing tensions between the two countries.
In addition to clarifying Trump's attitudes towards Islam, the pair also discussed Saudi investment in America, with the Prince crediting Trump for improving America's economic climate.
Iranian pilgrims did not participate in the Haj a year ago for the first time in almost three decades, after Riyadh and Tehran failed to agree on security and logistics.
The visit of King Salman to China has underscored the important position enjoyed by the Kingdom in the global community, business leaders told local media.More news: Fillon Placed Under Probe
"The ministry of hajj and the Iranian organization have completed all the necessary measures to ensure Iranian pilgrims perform hajj 1438 according to the procedures followed by all Muslim countries", the official Saudi Press Agency said in a statement Friday, referring to the Islamic calendar. Iran previously opted out of the hajj between 1988 and 1990 after fighting between Iranian nationals and Saudi police left around 400 people dead during the 1987 pilgrimage.
The visit reflects the Kingdom's endeavors to cement Islamic solidarity and encourage the ranks of united Muslims to allow them to enjoy their true position among the world countries thanks to their enormous potentials and resources, he said.
The news agency said the kingdom had completed all arrangements for the Iranian pilgrims to return, without offering details.
The agreement comes as a promising development between the two countries as previous year Saudi Arabia broke off diplomatic relations with Iran after rioters stormed the Saudi Embassy in Tehran while protesting Saudi Arabia's execution of Nimr al-Nimr, an outspoken Shiite cleric who had criticized the Saudi royal family. Saudi Arabia has sought to increase its oil sales to China, also the world's second-largest oil market, after losing some of its market share to Russian Federation in 2016.