United States President Donald Trump said on Wednesday that he would end the popular US green card lottery as police said the radicalised Uzbek man who staged the deadly truck ramming in New York on Tuesday had entered the country under that programme.

The move could spell the end to the US immigration hopes of millions of people around the world who have tried to win US residence permits through the programme since it was created 27 years ago.

“I am starting the process of terminating the diversity lottery programme,” Trump angrily told reporters.

“We have to do what's right to protect our citizens,” he said. “We will get rid of this lottery programme as soon as possible.”

The programme awards US permanent resident visas to around 50,000 applicants from around the world each year, opening the door as well for members of their broader families to follow them, so-called chain migration.

According to Trump, Sayfullo Saipov, identified by authorities as the man who ploughed a rented truck into cyclists and pedestrians on a New York City bike path on Tuesday, came to the country through visa lottery programme in 2010.

Saipov, 29, who was arrested after being shot by police, planned for weeks to undertake his attack in the name of the Islamic State (IS) group, following online instructions from the militant group, officials said.

New York Governor Andrew Cuomo said he was “radicalised domestically” only after he came to the country, “when he started to become informed about ISIS and radical Islamic tactics.”

Closing doors to immigration

Trump's threat would further close the doors to hopeful US immigrants. He ran for election last year promising a crackdown on immigration, including building a wall on the Mexican border and banning Muslim immigrants.

This year he has already slashed the country's annual refugee intake by more than 50 per cent to 45,000, tightened visa issuance around the world and ordered a ban on travellers from 11 unnamed “high-risk” countries. Refugee experts say all but one have Muslim-majority populations; they do not include Uzbekistan.

The officially titled Diversity Lottery Programme aims to diversify the origins of people granted permanent residence, so-called green cards, in the US.

In 2015, lottery applications were received for more than 14 million people, and 49,377 won green cards, including 2,524 Uzbeks.

Trump said he wants to move US immigration to a “merit-based system” and not allow immigrants to bring their extended families.

“We want to get rid of chain migration,” he said.

Republicans in Congress have tried for several years to eliminate the visa lottery programme but were stifled by Democratic resistance.

Trump blamed the programme on Chuck Schumer, the senior Democratic senator from New York, even though it was resoundingly supported by both parties and signed into law in 1990 by a Republican president, George H.W. Bush.

“The terrorist came into our country through what is called the 'Diversity Visa Lottery Programme,' a Chuck Schumer beauty. I want merit-based” immigration, Trump tweeted.

Few US attacks by immigrants

Tuesday's incident was the second time the lottery has been tied to a terrorist attack inside the US. In July 2002, an Egyptian man whose wife entered the country on the green card programme shot two people dead at the ticket counter for El Al, the Israeli airline.

Otherwise, Trump's immigration crackdown would not have prevented any of the deadly terrorist attacks inside the US over the past 16 years.

Most have been perpetrated by US-born and radicalised perpetrators. And most have family ties to countries not covered by Trump's travel bans, Pakistan, Saudi Arabia, Afghanistan and others.

But Republicans expressed strong support for Trump's move.

“Yesterday's attack was an outrage, especially because it was entirely preventable,” said Senator Tom Cotton.

“The diversity visa lottery programme has long been deeply flawed, but now we see very clearly how it's a threat to our national security.”

Schumer rejected Trump's stance. “I have always believed and continue to believe that immigration is good for America,” he said in a statement.

And New York Governor Andrew Cuomo said Trump had politicised the situation.

“That was a bipartisan law that was passed that had basically no relevance to the facts of this situation,” he said.

“As I said before, you play into the hands of the terrorists to the extent you disrupt and divide and frighten people in this society. And the tone now should be the exact opposite. “