MECCA, Saudi Arabia (AP) — The annual Hajj pilgrimage, one of the Five Pillars of Islam, officially began Monday.

More than 1.5 million pilgrims have arrived in Saudi Arabia from outside the country, Saleh bin Saad Al-Murabba, commander of the Hajj passport forces, said Friday. The faithful have been pouring into the country for the Hajj against the backdrop of a tenuous ceasefire in the Iran war and related regional tensions and uncertainty.

Egyptian pilgrim Samya Abdul Moneim said she was grateful to God that she made it to the Hajj, which is required once in a lifetime of every Muslim who can afford it and is physically able to make it.

"I am in a state of blessing and happiness," she said in Mecca on Sunday. "It's an indescribable feeling, truly. I mean, thank God, I am in a blessing."

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Typically on the first day, many pilgrims in Mecca converge on a vast tent camp in the nearby desert. Ahead of that, pilgrims have been circling the cube-shaped Kaaba in the Grand Mosque in sweltering temperatures. For pilgrims, Hajj can be a deeply moving spiritual experience and a chance to seek God's forgiveness and the erasure of past sins. Pilgrims perform the Hajj rituals over several days.

This Hajj "is, in effect, a hard reset for me," Youssef Chouhoud, a political scientist at Christopher Newport University in Virginia, said Monday from the tent city of Mina. "I pray that I emerge on the other side of this journey with a new sense of purpose and the discipline to see it through."

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Around him, many pilgrims were resting and refueling, he said via WhatsApp, noting how demanding the pilgrimage is.

"It is for many pilgrims the most difficult thing they will ever do in their lives," he said. "But nothing this meaningful is ever going to be easy."

He found it inspiring "to see so many who have sacrificed so much to be here ... only to compete with one another in giving charity and helping each other along the way," he said. "All this in the hope that their intentions and actions may be accepted by their Lord."

Pilgrims brave intense heat

Many spend years hoping and praying to one day perform the Hajj or saving up money and waiting for a permit to embark on the trip.

As they brave the intense heat to perform religious rituals, many pilgrims have been using umbrellas for shade and carrying handheld fans. Volunteers hand out water bottles to help them stay hydrated and fans spray fine mists of water.

On Saturday, U.S. President Donald Trump said a deal with Iran on the war, including opening the Strait of Hormuz, has been "largely negotiated" after calls with Israel and other allies in the region. He described it as a "Memorandum of Understanding pertaining to PEACE" that still must be finalized by the United States, Iran and the other countries that participated in the calls. That capped a week in which the U.S. weighed a new round of attacks on Iran.

Ahead of the trip for Hajj, some have said they were leaning on their faith as they embark on the journey amid the tensions and that they were feeling immense gratitude for the opportunity to go.

Hajj brings together large numbers of Muslims of diverse races, ethnicities, languages and economic classes, creating a sense of unity for many.

Regional tensions and Hajj travel plans

With uncertainty and global concerns high, authorities in Indonesia, home to the world's largest Muslim population, have in the run-up to the Hajj season emphasized contingency planning for the pilgrimage and issued instructions to ensure that additional travel costs not be passed on to Indonesian pilgrims.

In India, home to a large Muslim minority, pilgrimage planning has proceeded largely as normal, but high fuel prices have pushed up travel costs for pilgrims.

A reopening of the strait would begin to ease a worldwide energy crisis sparked by the U.S. and Israeli attacks on Iran on Feb. 28, which led Tehran to effectively close the waterway. Prices have spiked for oil, gas and several related products, jolting the world economy. The U.S. has blockaded Iranian ports for over a month, and Trump on Sunday said the blockade "will remain in full force and effect until an agreement is reached, certified, and signed."

In response to the U.S.-Israeli attacks, Iran has launched retaliatory strikes and the conflict widened. A fragile ceasefire was reached in April.

In Saudi Arabia, pilgrims have been doing the ritual circuit around the Kaaba since arriving in Mecca over recent days. Pilgrims in Mina will camp there and pray and worship.

On Tuesday, in what is considered the pinnacle of the pilgrimage, the pilgrims will stand on the plain of Arafat, where they praise God, plead for forgiveness and make supplications. Many carry prayer requests from loved ones and raise their hands in worship with tears streaming down their faces.

Fam reported from Winter Park, Florida. Associated Press writers Niniek Karmini in Jakarta, Indonesia, and Sheikh Saaliq in New Delhi contributed to this report.