Pope John Paul II had to cancel plans to visit Iraq at the turn of this century as escalating tensions with the United States undermined negotiations with Saddam Hussein for a papal visit. Pope Benedict XVI had to cancel his plans because of security concerns.

And almost until the moment he boarded the papal plane in Rome en route to Baghdad on Friday, the Vatican cautioned that the visit by Pope Francis could be called off at any time.

But despite concerns about the coronavirus and a precarious security situation — with a military base in northern Iraq targeted by a missile strike two days before his scheduled departure — Francis held firm in his desire to visit the long-suffering and fading Christian community in the war-torn nation.

Francis has set an ambitious agenda that will take him from the Plains of Nineveh, where Christianity traces its roots back about 2,000 years, to the northern region of Kurdistan, where his three-day trip culminates on Sunday evening with an outdoor Mass for thousands at Franso Hariri soccer stadium in Erbil.

Christians waited for Pope Francis at Baghdad International Airport on Friday, above, as buses brought in other faithful, below.

Pope Francis waving to the crowd upon his arrival in Baghdad.

Outside the presidential palace on Friday in Baghdad, where Pope Francis will meet with President Barham Salih.

Francis arriving at Our Lady of Salvation Church in Baghdad. The church was the site of a 2010 Qaeda attack that accelerated an exodus of Christians from Iraq.

A poster promoting the trip of Pope Francis in Erbil, Iraq.

Preparations before the pope’s trip have been ongoing, including at Al-Tahira church in Qaraqosh, below.

Sewing the flag of Vatican City at a printing house in Erbil.

Security members from the prime minister’s office carrying out precautionary measures inside St. Joseph’s Church.

A police officer standing guard outside the Chaldean Catholic Church of St. Joseph in Baghdad.

A joint Kurdish and Christian orchestra and choir rehearsing at a stadium in the Kurdish town of Erbil on Monday.

Repairing the Grand Immaculate Church in Qaraqosh before the pope’s visit.

A piece of graffiti depicting Pope Francis on concrete walls surrounding Our Lady of Salvation Church in Baghdad.