"My thoughts go notably to the people who had to leave their homes to escape the horrors of war, in search of a better life," the pontiff said in a video message opening an online meeting organised by the Vatican with dozens of Catholic NGOs.

He added: "We must work to ensure that the Christian presence in these lands continue to be what it has always been: a sign of peace, progress, development, and reconciliation between peoples."

His comments follow the surprise announcement on Monday that he plans to become the first-ever pope to visit Iraq, with a trip in March that will include visits to Baghdad and Mosul.

Iraq's historic and diverse Christian communities have been devastated by the sectarian warfare that followed the 2003 US-led invasion and the IS sweep through a third of the country in 2014.

William Warda, co-founder of the Hammurabi Human Rights Organisation, estimates there are now just 400,000 Christians in Iraq, down from 1.5 million in 2003.