The fate of thousands of undocumented immigrants will depend on how Americans vote this presidential election — they could either face deportation or receive work permits. Democratic presidential nominee Hillary Clinton and her rival Republican nominee Donald Trump vary a great deal on the issue of immigration.

As the days counting down to Election Day inch closer, here is a look at their immigration policies:

Donald Trump

The 70-year-old Republican nominee called America’s current immigration policy “worse than anyone’s ever realized it” in his Arizona speech and has called for a ban on people fleeing terrorism in their native countries. He believes the U.S. should work on improving the lives of its citizens rather than offering benefits to immigrants.

The following are the core ideas in Trump’s immigration policy:

1. Construction of the U.S.-Mexico Border Wall

Trump proposed the building of a border wall that he insists Mexico will pay for. The real estate mogul has not been clear about the estimated cost of this wall, which he says could be anywhere between $5 billion and $10 billion. Mexican President Enrique Peña Nieto has flatly dismissed the idea that Mexico would pay for the wall.

The “impenetrable” wall will feature “the best technology, including above-and below-ground sensors, towers, aerial surveillance and manpower to supplement the wall, find and dislocate tunnels, and keep out the criminal cartels, and Mexico will pay for the wall,” according to Trump's campaign.

2. Citizenship

Trump proposes to select immigrants based on “their likelihood of success in the U.S. and their ability to be financially self-sufficient.” He said that he would do away with birthright citizenship, according to which automatic citizenship is provided to any child born in the country, regardless of their parents’ status.

3. Deportation

Trump has adopted a hard-line stance on deportation saying any undocumented immigrant will be subject to deportation. He has also called for the deportation of "criminal aliens" insisting that his administration will ensure that the native countries of these "criminal aliens" will take them back.

His administration will also cut funding for sanctuary cities where undocumented immigrants are not prosecuted just for their illegal status. Trump said in his Arizona address: “Cities that refuse to cooperate with federal authorities will not receive taxpayer dollars, and we will work with Congress to pass legislation to protect those jurisdictions that do assist federal authorities.”

4. The American Worker

The 70-year-old insists that his administration would work for the benefit of the American worker. He said foreign workers are the reason behind the high unemployment rates in the U.S. and the reason why American workers are struggling to earn a middle-class wage.

Under Trump’s administration, employers will have to look at American workers first before turning to foreign ones for recruitment. He added that he would call for a temporary freeze on awarding green cards to foreign workers until American workers are hired.

immigration U.S. Democratic presidential candidate Hillary Clinton and Republican presidential candidate Donald Trump shake hands after the second presidential debate at Washington University in St. Louis, Missouri, Oct. 9, 2016. Photo: ROBYN BECK/AFP/GETTY IMAGES

Hillary Clinton

The former secretary of state promised to integrate the thousands of undocumented immigrants into the American society presenting herself as an advocate of comprehensive immigration reforms that aim at keeping immigrant families together.

These are the core ideas of Clinton’s immigration policy:

1. Immigration Legislation

Clinton pledges to pursue a new immigration legislation in her first 100 days in office that would create a path to citizenship for qualifying undocumented immigrants. She said that she would use executive action to protect undocumented immigrants from deportation ensuring that children aren’t deported and families stay together.

“I think it’s important that we move to our comprehensive immigration reform, but at the same time, stop the raids, stop the round-ups, stop the deporting of people who are living here doing their lives, doing their jobs, and that's my priority,” she reportedly said during a Democratic debate in March.

Clinton said that she would work with Congress in getting rid of the three- and 10-year bars, which impose time limits on the undocumented immigrants to either attain a legal status or leave the country as the period ends. Clinton described this as a “heartbreaking dilemma.”

2. Detention Policies

Under the Clinton administration, family detention for parents and children will end and private immigrant detention centers will be closed. Families who don’t pose a threat to the U.S. will be offered cost-effective alternatives instead of detention, she said.

3. Promoting Naturalization

Clinton will look to expand fee waivers to ease naturalization costs while increasing access to language programs. She pledged to increase access to education to help immigrants with the naturalization process.

Clinton also wants to expand access to the Affordable Care Act so it is available to immigrants as well. “Families who want to purchase health insurance should be able to do so,” her policy reads.

4. Humane Enforcement of Immigration Laws

Clinton vowed for a more dignified approach to immigration policy adding that immigrants who pose a threat to the U.S. will be detained and deported but refugees seeking asylum in the U.S. will “have a fair chance to tell their stories.”