Donald Trump campaigned on a detailed and extensive to-do list for his first day in office. A day before his swearing-in, his team was being coy about when and how he plans to cross items off it.

As he's assembled his new government, Trump has backed off some of his promised speed, downplaying the importance of a rapid-fire approach to complex issues that may involve negotiations with Congress or foreign leaders. On others issues, he's affirmed his plan, indicating significant policy announcements may be teed up in the first hours and days of the Trump administration.

On Thursday, transition spokesman Sean Spicer said Trump would issue two executive orders on trade soon. On his Day One list, Trump said he would formally declare the United States' intention to withdraw from the 12-nation Trans-Pacific Partnership trade deal, which he vigorously opposed during his campaign as detrimental to U.S. businesses and workers. He also promised to declare his intention to renegotiate the 23-year-old North American Free Trade Agreement or withdraw from the deal.

"I think you will see those happen very shortly," Spicer said. 

Other issues likely to see early action include energy, where he's likely to undo regulations on oil drilling and coal, and cybersecurity, where he has already said he will ask for a report on the strength of the nation's cyber defenses within 90 days of taking office.

He's also made broad promises to upend immediately President Barack Obama's immigration policies, although some of those vows may be difficult to keep.

The president-elect has said he sees Monday as the first big work day of his administration, his effective Day One. Trump said at his first post-election news conference last week that people would ``have a very good time at the inauguration'' but his team planned ``some pretty good signings on Monday and Tuesday and Wednesday and Thursday and Friday, and then also the next week.''

The real estate mogul is expected to sign some paperwork on Friday. He must formally nominate members of his Cabinet, in order to allow some of them to be voted on by the Senate. The transition team has also said he may sign executive orders -- some logistical, others focused on his agenda -- that will kick off his administration.

"Specifically we've focused in the president-elect's direction on a Day One, Day 100 and Day 200 action plan for keeping our word to the American people and putting the president-elect's promises into practice,'' Vice President-elect Mike Pence said during a briefing with reporters on Thursday. Pence, who chaired Trump's transition team, added: "We are all ready to go to work. We can't wait to get to work for the American people.''

Trump's Day One plan was an ambitious and specific list. It includes proposing a constitutional amendment to impose term limits on members of Congress, imposing a hiring freeze for federal workers, and beginning to remove immigrants who are criminals and living in the country unlawfully. 

The list includes "cancel every unconstitutional executive action, memorandum and order issued by President Obama.'' Given Trump's objections to many of Obama's policies, that category could involve some dramatic changes.

Among those would be cancellation of the Deferred Action for Childhood Arrivals program, or DACA, which has protected about 750,000 young immigrants from deportation. The program also offered those immigrants work permits.

If he makes good on his promise to terminate the program, Trump could chose to immediately cancel the deportation protection and revoke the work permits, or he could opt to block new enrollment and allow those already approved to keep their work permits until they expire.

Trump has said he plans to focus immigration enforcement efforts first on criminals, a group he said could including 2 million to 3 million people.

Trump also pledged to "move criminal aliens out day one'' in operations with state, local and federal authorities. That promise will be harder to keep on his first few days in office. Jurisdictions around the country objected to helping enforce federal immigration laws. He will also face a shortage of jail space. The government has enough money to keep 34,000 people in immigration jails at a time and has recently detained more than 40,000 people because of a surge of immigrants arrested at the Mexican border last year.

Also on Trump's list was labeling China a currency manipulator. But Trump said in an interview with The Wall Street Journal last week that he no longer planned to do that on the first day. "I would talk to them first,'' he said.

If Trump opts for a slower pace, it may be because he is still setting up his administration. He is awaiting confirmation of Cabinet choices and staffing federal agencies and has left vital spots such as the chairman of the Council of Economic Advisers unfilled so far. Instead of unveiling an updated series of policies, Trump devoted part of his transition to meeting with prominent CEOs and touting jobs announcements by their companies. His team has also spent weeks reviewing Obama's executive actions to determine which ones can be eliminated quickly.

Trump's team also faces the daunting process of naming a Supreme Court justice to fill the vacancy left by the late Justice Antonin Scalia. Trump has said he will announce a nominee in about two weeks.

Trump's promises of swift changes have been cheered on by congressional Republicans, who have seen their agenda blocked by Obama for the past eight years. Pence and Trump aides have shared some details for the first few days with House leadership and told lawmakers to expect the incoming president to move quickly to undo Obama's legacy.

"There is a call of history and that calls us to put America back on the rails again and we've now been delivered the tools to do this by the voters,'' said Rep. Steve King, R-Iowa. (AP)