President Donald Trump's executive orders on immigration include plans to build a border wall, deport more people and crack down on sanctuary cities.

A temporary ban on incoming refugees and a halt to visas for immigrants from certain countries could also be in the offing.

The measures unveiled this week provide the most detailed information we've seen so far about Trump's overhaul of the US immigration system. But there are many unanswered questions about how things will play out.

Here are seven key questions we're asking:

1. How much will it cost?

That's the more-than-$10-billion question. Trump has used that price tag to estimate how much building a wall on the US-Mexico border would cost. And the wall is only the beginning.

The numerous initiatives outlined in his executive orders also include plans to hire at least 15,000 more people (5,000 new Border Patrol agents and 10,000 additional immigration officers). That could cost another few billion dollars, based on the Department of Homeland Security's 2017 budget request, which asked for $7 billion to hire more than 40,000 officers.

Another possible big-ticket item: plans to build more detention centers.

2. Where will the money come from?

As the New York Times pointed out in a story on Wednesday, no matter what Trump prioritizes, Congress has the checkbook.

The President does have some leeway to shift funds between departments, but money for major initiatives will need to come from lawmakers.

Even if Congress has to foot the bill up front, Trump has vowed to make Mexico pay for the border wall eventually -- something Mexican officials say they'll never do. The latest possibility floated by administration officials: imposing a 20% tax on imports from Mexico to pay for the border wall.

3. What happens to the Dreamers?

On the campaign trail, Trump touted his plans to dismantle his predecessor's crowning immigration achievement: the program that prevented about 750,000 undocumented immigrants who were brought to the United States as children from being deported. The Deferred Action for Childhood Arrivals program helps the so-called Dreamers get driver's licenses, enroll in colleges and secure jobs.

And there's little doubt that it will end up on the chopping block.

But so far, Trump's administration is still accepting applications for the program.

4. How will this impact sanctuary cities?

One of Trump's executive orders says the federal government will cut funding to cities that refuse to cooperate with federal immigration officials.

That means federal grants that provide millions of dollars to local governments could be at stake.

These so-called sanctuary cities say they're committed to protecting their undocumented residents from possible deportation, and they're banding together as they brace for what's likely to be a contentious legal battle.

Already New York Mayor Bill de Blasio has said he's ready to go to court over the issue, and it's likely others will follow suit.

5. When will we start to see these changes happening?

It's unlikely many significant changes in the way the US handles immigration will happen overnight.

But even a small memo outlining priorities can have a big impact on how individual cases are handled. We saw that in 2014, when the Obama administration issued new guidelines that shifted enforcement efforts to focus on recent border-crossers and criminals who posed a threat to public safety. That change meant some cases were dropped altogether, while others were scheduled for court dates several years in the future.

Trump's executive orders would crack down more severely on immigrants accused of criminal offenses, and could signal that cases that might have been dropped before will now become a priority.

6. And how long will they take?

Just because something shows up in an executive order doesn't mean it will become reality.

President Obama tried a similar approach in 2014 to expand the DACA program and create a new program to help the Dreamers' parents.

Those programs faced swift legal challenges and were tied up in the courts for years before the Supreme Court deadlocked over whether they were constitutional, effectively killing the measures that would have helped more than 4 million undocumented immigrants come out of the shadows.

7. Will these measures impact people who aren't undocumented immigrants or refugees?

In all likelihood, yes. But exactly how remains unclear.

Activists quickly slammed a reported policy that would bar people from Iraq, Syria, Iran, Sudan, Libya, Somalia or Yemen from entering the US for 30 days, calling it Islamaphobic and tantamount to a "Muslim ban."

The details of the policy haven't been officially announced, and it's unclear how it would apply to immigrants from those countries who have already obtained visas to be in the United States to study or work.

It's also unclear how immigration authorities will approach Trump's intensified focus on deporting criminals. But it's possible that green card holders and other legal residents could end up in deportation proceedings if they have any charges on their records.

CNN's Tal Kopan and Lisa Rose contributed to this report.