BAGHDAD: A US contractor died of cardiac failure after rocket fire hit an Iraqi base hosting coalition troops Wednesday, the Pentagon said, just two days ahead of Pope Francis' visit to the country.

Around 10 rockets slammed into the sprawling Ain al-Assad military base in Iraq's western desert after several weeks of escalating US-Iran tensions on Iraqi soil.

"A US civilian contractor suffered a cardiac episode while sheltering and sadly passed away shortly after," the US Defense Department said, noting there were no current reports of injuries among US service personnel.

Francis was quick to say he would go ahead with the first-ever papal visit to the war-scarred country so as not to "disappoint" the Iraqi people.

"The day after tomorrow, God willing, I will go to Iraq for a three-day pilgrimage," the 84-year-old pontiff said in his Wednesday address. "For a long time I have wanted to meet these people who have suffered so much."

Ain al-Assad hosts Iraqi forces and US-led coalition troops helping fight the Islamic State group. It is also a base for drones the coalition uses to surveil jihadist sleeper cells. The base's rocket system was "engaged in defense of our forces," said the Pentagon, noting Defense Secretary Lloyd Austin had been briefed and was closely monitoring the situation.

Iraqi security forces were on the scene and investigating, but it was too early to attribute responsibility, it added.