The Chaldean Catholic Patriarch of Baghdad Louis Raphael Sako has described the situation in the Middle East following the US killing of Iran's top military leader as a "volcano about to erupt".

Qasem Soleimani was killed last Friday in a US drone strike on the orders of President Donald Trump, prompting Iran to promise "forceful revenge". 

Sako has asked both Christians and Muslims in Iraq to pray for peace as he spoke of his fears in a homily for Epiphany that innocent people will be fuel for the "fire". 

"The baptism of Jesus Christ revealed the extent of God's love for the human being He created, in order to live a fraternal relationship of love and peace with each other," he said. 

Last week, in a statement, Sako said Iraqis were "still in shock" over the killing of Soleimani.

"They have fears of having Iraq turned to a battleground, rather than being a sovereignty homeland, capable of protecting its citizens and wealth," he said. 

"In such critical and tense circumstances, it is wise to hold a round table meeting for all the parties concerned to have a reasonable and civilized dialogue that spares Iraq the unexpected consequences.

"We implore the Almighty God to grant Iraq and the region a peaceful, stable, secure and 'normal life' that we are longing for."

Huge crowds turned out for Soleimani's funeral in Tehran on Monday.  His successor, Esmail Ghaani, vowed that "certainly actions will be taken". 

"God the Almighty has promised to get his revenge, and God is the main avenger," he said, according to The New York Times. 

Soleimani's daughter, Zeinab, delivered the eulogy, in which she warned of a "dark day" for the US and Israel. 

"You crazy Trump, the symbol of ignorance, the slave of Zionists, don't think that the killing of my father will finish everything," she said.

A source identified only as Ali, from Global Catalytic Ministries, told Mission Network News that Christians could suffer as a result of Soleimani's death. 

"Iran, and many Middle Eastern countries look at Christianity as a Western influence, and especially as a US influence," Ali said, adding that whenever they want to "make a statement to Western culture, they always arrest Christians or do worse things ... beat them, torture them, kill them".