The Trump administration has issued tough guidelines to widen the net for deporting illegal immigrants from the US, and speed up their removal.
Undocumented immigrants arrested for traffic violations or shop-lifting will be targeted along with those convicted of more serious crimes.
All 11 million undocumented foreigners in the US could be affected.
But the plan leaves in place Obama-era protections for immigrants who entered the US illegally as children.
The Department of Homeland Security (DHS) plans to hire an extra 10,000 agents for Immigration and Customs Enforcement and 5000 more border patrol officers.
"With extremely limited exceptions, DHS will not exempt classes or categories of removal aliens from potential enforcement," the department said.
"All of those in violation of the immigration laws may be subject to enforcement proceedings, up to and including removal from the United States."
What's changed from the Obama era?
During his eight years in office, Barack Obama instructed US immigration officials to focus deportation efforts on undocumented migrants who were convicted of serious crimes or recent arrivals captured near the US border.
Donald Trump's immigration order marks a sharp break with those policies. Instead - according to the Department of Homeland Security implementation memos - the Trump administration essentially will "prioritise" the deportation of almost all undocumented immigrants, everywhere.
The Homeland Security Department's list of prioritised "removable aliens" is so broad as to include just about every class of undocumented immigrant - with only a carve-out for individuals who entered the US as children.
All this will require more money and manpower - and the Trump administration is going to ask Congress for the former and go on a hiring spree to address the latter. Local and state law-enforcement officials will also be allowed to arrest unauthorised immigrants.
While Mr Obama aggressively enforced immigration law and ramped up deportations in some areas and at some times, there were notable instances where he de-emphasised action. In the Trump era immigration authorities are now being given the power to make a sea-to-sea, border-to-border push.
What is in the new orders?
The two memos released on Tuesday by the agency suggest individuals apprehended in the US would need to prove that they have been in the country continuously for two years.
Otherwise, agents could expedite their removal with no court proceeding.
Some of the new priorities include:
- Expanding deportations to undocumented immigrants who have been charged with a crime, abused public benefits, misrepresented themselves or pose a risk to public safety - effectively allowing agents to arrest any illegal immigrant they encounter
- End US policy to release those caught on the border and instead place them into detention centres until their cases are resolved
- Call for authorities to prosecute parents who help smuggle their children into the country
- Allow planning to begin on an expansion of the border wall along the US southern border
Homeland Security Secretary John Kelly wrote in one of the memos: "The surge of illegal immigration at the southern border has overwhelmed federal agencies and resources and has created a significant national security vulnerability to the United States."
Mr Kelly's memo also includes instructions to enforce a long-standing provision of the US Immigration and Nationality Act that allows authorities to send some people caught illegally at the border back to Mexico, regardless of where they are from.
It is unclear whether the US has authority to force Mexico to accept foreigners.
Where has this guidance come from?
President Trump followed through on his campaign promise to tighten border control and build a wall along the US-Mexican border by signing executive orders on immigration just days after taking office in January.
The new DHS memos are meant to implement Mr Trump's immigration actions as well as enforce existing immigration law.
But the new guidelines declined to explain how Mr Trump's border wall would be funded and where undocumented immigrants apprehended in the crackdown would be detained.
The memos instruct agents to "allocate all available resources to expand their detention capabilities and capacities", but Congress would probably need to allocate money to build new detention centres.
Mr Trump's immigration policies have prompted protests on both sides of the border. Tens of thousands of people took to the streets in more than a dozen Mexican cities last week to protest against the new president's plan for a border wall.