Vast crowds of robed pilgrims made solemn circles around the Kaaba Sunday as the biggest hajj pilgrimage in years began in the heat of the Saudi summer.

Islam's holiest site is expected to host more than two million worshippers from 160 countries during the annual rites that could break attendance records, with 1.6 million foreigners already arrived by Friday evening.

The hajj began early on Sunday with the "tawaf" -– the circumambulation of the Kaaba.

"I am living the most beautiful days of my life," said Abdel-Azim, a 65-year-old Egyptian as he performed the ritual.

"The dream has come true," said the retiree, who saved up for 20 years to pay the USD 6,000 fee to take part.

Hajj is one of the five pillars of Islam and must be undertaken by all Muslims with the means at least once.

A series of rites are completed over four days in Mecca and its surroundings in the west of Saudi Arabia.

Sunday night, pilgrims will start moving to Mina, about five kilometers from the Grand Mosque, ahead of the hajj's climax at Mount Arafat.