US President Donald Trump has defended his decision to suspend issuing of green cards till the end of the year, saying it was needed to give jobs to Americans.

Through an executive order, Trump, in April, had suspended issuing of green cards for 90 days. On Monday, he issued a proclamation which extended the suspension till December 31, 2020.

"So, we want to give jobs to Americans right now. Right now, we want jobs going to Americans," Trump told reporters in San Luis, Arizona on Tuesday when asked by reporters to explain the suspension order.

Trump, seeking another term in the White House in the November 3 presidential election, on Monday said the step was essential to help millions of Americans who have lost their jobs due to the economic crisis amidst the COVID-19 pandemic.

Trump said that the overall unemployment rate in the country nearly quadrupled between February and May of 2020 -- producing some of the most extreme unemployment rates ever recorded by the Bureau of Labor Statistics.

While the rate of 13.3 per cent unemployment in May reflects a marked decline from April, millions of Americans remain out of work.

With the current suspension in effect, the wait time for Indian technology professionals to get legal permanent residency in the US is now running into decades.

The US every year allocates only 1,40,000 green cards for all employment-preference immigrants, including accompanying family members.

Currently, there is a backlog of almost 10 lakh foreign nationals and accompanying family members lawfully residing in the United States. These applicants have been approved but are yet to receive employment green cards.

The backlog is projected to increase each year because the number of foreign workers who self-sponsor or are sponsored by their US employers for green cards each year exceeds the annual allocation.

In addition to this numerical limit, there is a statutory seven per cent per-country ceiling applied to each preference category, which prevents the monopolisation of employment-based green cards by foreign nationals from a single country.

This per-country ceiling has created decades-long waits for nationals from large migrant-sending countries such as India and China, a latest Congressional report said.