Geneva - Criticism of Republican presidential front runner Donald Trump spread internationally on Tuesday as the candidate defended his call to bar Muslims from entering the United States, calling it a necessary remedy for the growing threat of Islamist terrorism.
But his detractors, including the Office of the UN High Commissioner for Refugees(UNHCR), said Trump's campaign rhetoric is undermining efforts to resettle Syrian refugees and playing into the hands of Islamist extremists.
"We are concerned that the rhetoric being used in the election campaign is putting an incredibly important resettlement programme at risk - a resettlement programme which is meant for the most vulnerable people of wars that the world is unable to stop," said Melissa Fleming, spokesperson for the UN refugee agency.
British Prime Minister David Cameron said through a spokesperson that he believes Trump's comment is "divisive, unhelpful and quite simply wrong".
Najib Ghadbian - the US representative of the Syrian National Coalition, a coalition of Syrian opposition groups, charged that such divisive rhetoric undermines the fight against the Islamic State extremist group, also known as ISIS.
"The United States has a long and proud tradition of providing refuge to those in need," he said in a statement. "Trump's hate-mongering only undermines that venerable tradition and plays right into the hands of ISIS and other extremist groups."
The US is the largest recipient of refugees in the UN refugee agency's global resettlement programme and is set to receive 75 000 people from the Middle East, Africa and elsewhere this year, the agency said.
There is a lengthy screening process and people are prioritised according to their vulnerability in their countries of origin. The most stringent background checks are conducted for those entering the US, Fleming said.
Discrimination based on religion is against "every convention that we know of in aiding people in humanitarian emergencies and of course in resettlement", she said.
Trump's statement on Monday followed last week's shooting spree by what the US Federal Bureau of Investigation said was a "radicalised" Muslim couple who killed 14 people and wounded 21 in San Bernardino, California.
The Republican candidate and businessman appeared on television news channels on Tuesday defending his policy proposal and making frequent references to the September 11 2001, terrorist attacks.
In an interview with CNN, he insisted that banning Muslims was necessary "until our representatives figure out what the hell is going on" without specifying how exactly the policy would work.
On MSNBC, he said all people should be asked if they are Muslim upon entering the US and, if they answer affirmatively, they should be turned away.