Persecution of Christians in the Middle East amounts to 'genocide', Vice President Mike Pence said, vowing it 'must' and 'will' end.
Donald Trump's number two listed atrocities by 'the barbarians known as ISIS' and said the group 'is guilty of nothing short of genocide'.
Speaking at the National Catholic Prayer Breakfast on Tuesday, Pence praised the work of Catholics in America before focusing on persecution in the Middle East.
'In Iraq we see ancient churches demolished, priests and monks beheaded, two millennia old Christian traditions in Mosul virtually extinguished,' he said.
'Christianity faces unprecedented threats in the land where it was given birth and an exodus unlike since the days of Moses.'
He added: 'Whether in Mosul, Iraq or Syria, followers of Christ have fallen 80 per cent in the last decade and a half.'
Insisting religious freedom is a 'foreign policy priority' for Donald Trump's administration, he said: 'This must end. This will end.'
He continued: 'Under President Donald Trump, America will continue to condemn persecution of any faith in any place at any time.
'We will confront it with all of our might,' he said, adding the United States would not relent 'until we drive the cancer of terrorism from the face of the earth'.
Pence, a devout evangelical raised in an Irish Catholic family, received a standing ovation after concluding by saying how proud he is to be alongside a president who 'stands without apology for the sanctity of human life'.
'President Donald Trump stands with the most vulnerable: the aged, the infirm, and unborn,' he said.
He urged Catholics to see Trump as an 'ally' after the White House reinstated a policy that blocked foreign aid to groups that carry out abortions and appointed the conservative Neil Gorsuch, who backed Catholic groups in past trials over religious liberty, to the US Supreme Court.
'Life is winning in America again,' said Pence.
