The Bangladeshi-origin man accused of triggering a blast in New York City, came to the US by using a family immigrant visa sponsored by his uncle who had migrated through the diversity lottery visa programme, atop Trump administration official said on Wednesday.
Akayed Ullah, 27, on Monday triggered a blast with acrude homemade device at a metro station that injured three people.
He was on Tuesday charged with criminal possession of a weapon, supporting an act of terrorism and making a 'terroristic threat'.
Ullah migrated to the US from Bangladesh some seven years ago and is a green card holder, a lawful, permitted resident.
"He came to this country based on a family connection to a US citizen, who was a Bangladeshi national.
The citizen in question was his uncle, and that US citizen many years ago came to this country originally as a visa lottery winner," Lee Francis Cissna, director of US Citizenship and Immigration Services (USCIS) told White House reporters.
Following the attempted terrorist attack, US President Donald Trump has called for doing away with family based migration system, which is also called chain migration.
"There have now been two terrorist attacks in New York City in recent weeks carried out by foreign nationals on green cards.
The first attacker came through the visa lottery and the second through chain migration," Trump told reporters at the White House on Wednesday.
"We're going to end both of them: The lottery system and chain migration. We're going to end them. Fast. Congress must get involved immediately, and they are involved immediately and I can tell you we have tremendous support. They will beended," Trump said.
Cissna said family based migration in 2015, for instance, accounted for about 72 per cent of the immigrants and only sixper cent, or about 1 out of 15, came based on an employment or job connection, job offer.
Trump has been advocating for amerit-based immigration system. In the family-based migration category, there are multiple categories of people.
The principle category of family-based immigrant are called immediate relatives.
These are people who are the spouses or children, nuclear family members of US citizens.
In a given year, there are about half a million people inthat category.
In fiscal year '16, in that category, these are people who are the nuclear family members of US citizens, there were about 566,000 people that immigrated.
An additional category in the family-based universe are what are called preference categories.
These are more extended family connections. These include unmarried sons and daughters of US citizens. Second category, spouses of green card holders, unmarried sons and daughters of green card holders.
Third category, married sons and daughters of US citizens.
Fourth category is brothers and sisters of US citizens and their children.
"And that's the category that Monday's suspect came inunder. So the suspect in Monday's bombing came in under the most extreme, remote possible family-based connection you can have under current US immigration law.
That being the child of the sibling of a US citizen. Under the employment-based categories, that's a much smaller number," Cessna said, adding that only 140,000 slots are allocated in a year to that category.
Cessna said about 50,000 people come to the US on diversity visa which is allotted through a lottery system.
Responding to a question, he said the program is "vulnerable to exploitation by terrorists" because it is acombination of the low-eligibility criteria and the ability to defraud the system.
"Fraud is pervasive, in the program. So, if you are amalafide actor and you want to use that program to come into this country, it's easy to fake a high school graduation certificate," Cessna said.