Obama to announce major US immigration changes
US President Barack Obama is set to announce his plans to use overriding executive powers to enact major changes to immigration policy.
He will unveil his strategy in a televised address on Thursday night, he said in a video posted on Facebook.
The action could lift the threat of deportation for up to five million undocumented migrants.
Republicans in Congress say such action would be beyond Mr Obama's authority and have vowed to fight the initiative.
Following the announcement, Congressman Paul Ryan warned the president's immigration order was a "partisan bomb" that will sour his relations with Congress.
White House spokesman Josh Earnest told reporters on Wednesday that the aim was to make illegal immigrants "fully contributing" members of society, for the good of the country.
Analysis by Thomas Sparrow, BBC Mundo:
Hispanics voted overwhelmingly for President Obama in both the 2008 and 2012 elections, in part because of his promise to repair what he called the country's "broken" immigration system.
But six years after he came to power, many Hispanics have become disappointed in the president by the lack of a comprehensive immigration reform.
Although there are still questions regarding how many undocumented immigrants will ultimately be covered by his unilateral actions and how easy it will be to implement them with a Republican-controlled Congress, the measures will probably play an important part in President Obama's remaining two years in the White House, as he seeks to build his legacy.
The announcement and its implementation could also have an impact on the 2016 election cycle, because both Democratic and Republican hopefuls will want to attract the increasingly important Hispanic vote.
It is thought the president will extend his "deferred action" plan (Daca) which allows young adults who were brought to the US illegally as children to stay and work.
The plan is to extend that right to more young people and to more parents of children who are US citizens or legal residents.
The number of those affected by the suggested policy could be as high as five million, out of a total of 11m illegal immigrants.
Other parts of the executive action reported by the media include:
- Increasing the number of high-tech workers allowed to live and work in the US
- An expansion of the existing deferred action plans that would move the cut-off date for children arriving to 2010
- Shift border security resources to the US southern border, according to reports.
At a news conference during a visit to Myanmar last week, Mr Obama said he had given the House of Representatives more than a year to come up with an immigration bill but they had failed to do so.
The Senate passed a far-reaching immigration bill in 2013, but the House has not taken up the legislation.
"There has been ample opportunity for Congress to pass a bipartisan immigration bill that would strengthen our borders, improve the legal immigration system and lift millions of people out of the shadows," he said.
"I said that if in fact Congress failed to act, I would use all the lawful authority I possess to try to make the system work better," he added. "And that's going to happen before the end of the year."
But Republicans in Congress said the president should work with them.
"We're going to fight the president tooth and nail if he continues down this path," House Speaker John Boehner earlier told reporters.
Some Republicans are pushing for the budget bill to include a statement prohibiting "the use of appropriated funds for the president's immigration machinations".
Such a move could provoke a block by the Democrats, or a veto by the president, which in turn raises the risk of a government shutdown.