Donald Trump has renewed calls for a ban on Muslims entering the United States following the deadly Orlando shooting and said if elected president he will  "suspend immigration" from countries with a "proven history of terrorism".

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The presumptive Republican presidential nominee on Monday redoubled calls for temporarily banning Muslims, saying that they would only be allowed in if they were "properly and perfectly" screened.

"When I'm elected, I will suspend immigration from areas of the world where there is a proven history of terrorism against the United States, Europe or our allies, until we fully understand how to end these threats," Trump told supporters in New Hampshire.

He did not specify what countries would be affected or whether the suspension would apply regardless of religion.

"We cannot continue to allow thousands upon thousands of people to pour into our country, many of whom have the same thought process as this savage killer."

In his fiery address, Trump incorrectly referred to the Orlando shooting suspect Omar Mateen as an Afghanistan native. Mateen was born in New York City to parents who emigrated from Afghanistan.

Despite the years-long vetting process refugees must go through to arrive in the US, Trump labelled America's immigration system as "dysfunctional", adding that authorities were unaware of who was in the country.

"Each year, the United States permanently admits more than 100,000 immigrants from the Middle East, and many more from Muslim countries outside the Middle East. Our government has been admitting ever-growing numbers, year after year, without any effective plan for our security," he said.

He accused his likely opponent, Hillary Clinton, of trying to expand immigration and refugee programmes to allow more Syrians in, calling the move a "Trojan horse."

The White House hopeful delivered a withering critique of US President Barack Obama's foreign policy, saying that intelligence agencies trying to stop attacks were being "held back by" the president.

Earlier on Monday, Obama said there was no clear evidence that the attack at a nightclub, which left 49 dead, was directed from abroad, pointing out that the killer had been influenced by "extremist propaganda" over the Internet.

Trump has been increasingly virulent in his remarks targeting Muslims since the deadly Paris attacks, and again after the San Bernardino shooting attack in California.

Source: Al Jazeera