American officials have claimed it was hit over international airspace by an Iranian surface-to-air missile in an "unprovoked attack".
Iran's paramilitary Revolutionary Guard said it shot the drone down when it entered Iranian airspace near the Kouhmobarak district in southern Iran's Hormozgan province.
This comes after the Trump administration accused Iran of being behind attacks on oil tankers in the Gulf of Oman last week.
The US President responded to the incident in a tweet on Thursday, saying: "Iran made a very big mistake".
Iran made a very big mistake!
— Donald J. Trump (@realDonaldTrump) June 20, 2019
Reverend Lazarus Yeghnazar, President of 222 Ministries - a charity that supports Christians in Iran - told Premier he was concerned the situation will continue to escalate.
He said: "Trump is as stubborn and as determined to pursue his own ambitions as the Iranians Ayatollah, so they have met each other's match."
Reverend Yeghnazar believes there is a strong possiblity of war and has urged the Christian community to pray.
He said: "I don't think anyone will blink and that will be causing millions of other deaths.
"If a war happens it will be so catastrophic, it will bring destruction to Iran and all around countries - I think we're descending towards that, so can we pray for peace."
He added: "When the governance of God comes and the authority of God comes, there is healing, there is peace."
Conflict has increased between the two nations following a decision by Donald Trump to withdraw from Tehran's nuclear deal last year.
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