Last year a total of 3.2 million faithful, including 1.75 million foreigners, performed the pilgrimage to Mecca, Islam's holiest site. Those from abroad came from 190 countries.
This year Riyadh expects about two million, after the ultra-conservative kingdom announced a crackdown on illegal pilgrims and imposed restrictions to cut foreigners by 20 percent and Saudis by 50 percent.
About 1.17 million pilgrims had already entered the Persian Gulf state by Saturday, according to immigration officials, and more are expected before Thursday's deadline for people to arrive before the hajj starts.
The pilgrimage is one of the five pillars of Islam that should be performed at least once in lifetime by every Muslim who is financially and physically capable.
This year, the pilgrimage starts on Sunday and ends on October 18.
Authorities in the kingdom have mobilized health services in Mecca and the holy sites which together have 25 public hospitals with 5,250 beds and hundreds of scattered medical centers.
The MERS virus, which appeared first in the kingdom last year, has killed 58 people worldwide, 49 of them in Saudi Arabia, according to official Saudi figures and the World Health Organization.
Saudi authorities have appealed to ill and elderly people to avoid the hajj this year although Health Minister Abdullah al-Rabia said last month he was optimistic the pilgrimage will pass without outbreaks of the deadly coronavirus.
There were no MERS outbreaks recorded at last year's hajj, nor during the Umrah, or minor hajj, season in July and August of this year.
Aside from the virus fears, Saudi authorities have also cited construction work to expand the Grand Mosque in Mecca as a reason to keep down the number of pilgrims allowed to perform this year's hajj.
The expansion work would increase the area of the mosque by 400,000 square meters (4.3 million square feet), raising its capacity to accommodate 2.2 million people at the same time.
The mosque houses the Kaaba -- the cube-shaped structure towards which Muslims worldwide pray.
NTJ/BA