US President Donald Trump is expected to announce that he will end protections for young immigrants who were brought into the country illegally as children, but with a six-month delay, people familiar with the plans said Sunday.

The delay in the formal dismantling of the Deferred Action for Childhood Arrivals, or DACA, programme would be intended to give Congress time to decide whether it wants to address the status of the so-called Dreamers in legislation, according to two people familiar with the president's thinking. But it was not immediately clear how the six-month delay would work in practice and what would happen to people who currently have work permits under the programme, or whose permits expire during the six-month stretch.

It also was unclear exactly what would happen if Congress failed to pass a measure by the considered deadline. Two people familiar with the president's thinking spoke on condition of anonymity because they were not authorised to discuss the matter ahead of a planned Tuesday announcement.

The president, who has been grappling with the issue for months, has been known to change his mind in the past and could still shift course. The plan was first reported by Politico Sunday evening.

Trump has been wrestling for months with what to do with the Obama-era DACA programme, which has given nearly 800,000 young immigrants a reprieve from deportation and the ability to work legally in the form of two-year, renewable work permits.

The expected move would come as the White House faces a Tuesday deadline set by Republican state officials threatening to continue sue the Trump administration if the president did not end the programme. It also would come as Trump digs in on appeals to his base as he finds himself increasingly under fire, with his poll numbers hanging at near-record lows.

Trump had been personally torn as late as last week over how to deal with what are undoubtedly the most sympathetic immigrants living in the US illegally. Many came to the US as young children and have no memories of or connections to the countries they were born in.

During his campaign, Trump slammed DACA as illegal "amnesty" and vowed to eliminate the programme the day he took office. But since his election, Trump has wavered on the issue, at one point telling The Associated Press that those covered could "rest easy."

Trump had been unusually candid as he wrestled with the decision in the early months of his administration. During a February press conference, he said the topic was "a very, very difficult subject for me, I will tell you. To me, it's one of the most difficulty subjects I have."

"You have some absolutely incredible kids — I would say mostly," he said adding: "I love these kids."

All the while, his administration continued to process applications and renew DACA work permits, to the dismay of immigration hard-liners.

News of the president's expected decision appeared to anger advocates on both sides of the issue.

"IF REPORTS ARE TRUE, Pres Trump better prepare for the civil rights fight of his admin. A clean DREAM Act is now a Nat Emergency #DefendDACA," tweeted New Jersey Sen Bob Menendez, a Democrat.

But Rep Steve King, an Iowa Republican who has called DACA unconstitutional, warned that a delay in dismantling it would amount to "Republican suicide."

"Ending DACA now gives chance 2 restore Rule of Law. Delaying so R Leadership can push Amnesty is Republican suicide," he wrote.

It would be up to congressional lawmakers to pass a measure to protect those who have been covered under the programme. While there is considerable support for that prospect among Democrats and moderate Republicans, Congress is already facing a packed fall agenda and has had a poor track record in recent years in passing immigration-related bills.

House Speaker Paul Ryan and a number of other legislators urged Trump last week to hold off on scrapping DACA to give them time to come up with a legislative fix.

"These are kids who know no other country, who are brought here by their parents and don't know another home. And so I really do believe that there needs to be a legislative solution," Ryan told Wisconsin radio station WCLO.

The Obama administration created the DACA program in 2012 as a stopgap to protect some young immigrants from deportation as they pushed unsuccessfully for a broader immigration overhaul in Congress.

The program protected people in the country illegally who could prove they arrived before they were 16, had been in the United States for several years and had not committed a crime while being here. It mimicked versions of the so-called DREAM Act, which would have provided legal status for young immigrants but was never passed by Congress.

As of July 31, 2015, more than 790,000 young immigrants had been approved under the program, according to U. Citizenship and Immigration Services.

The House under Democratic control passed a Dream Act in 2010 but it died in the Senate. But since Republicans retook control of the House in late 2010, it has grown increasingly hardline on immigration, killing the Senate's comprehensive immigration bill in 2013 and failing to even take up a GOP border security bill two years later because of objections from conservatives.

Many House Republicans represent highly conservative districts. The primary upset of the former House Majority Leader Eric Cantor to a conservative challenger in 2014 in a campaign that cast him as soft on illegal immigration convinced many House Republicans that pro-immigrant stances could cost them politically.

So despite Ryan's personal commitment on the issue and his rhetoric in favor of the young immigrants, action to protect them may be unlikely in the House — absent intense lobbying from Trump.