Administration officials have said existing USA asylum rules encourage illegal immigration and bog down legitimate claims.
New regulations will block migrants from claiming asylum if they do not come to an official border crossing.
The move would largely affect migrants from Central America's Northern Triangle - Guatemala, Honduras and El Salvador - who cross the U.S. border with Mexico to flee violence and poverty in their home countries.
Trump is expected to sign the order on Friday before leaving on a trip to Paris.
Later, at a campaign rally in Missouri, Trump offered additional remarks on the topic, saying, "Under this plan, the illegal aliens will no longer get a free pass into the country by lodging meritless claims in seeking asylum". Those forms of protection include "withholding of removal" - which is similar to asylum, but doesn't allow for green cards or bringing families - or asylum under the United Nations Convention Against Torture.
The new changes were likely to be met with legal challenges, too.
The American Civil Liberties Union said that right of asylum must be granted to anyone entering the country, regardless of where they were. "It is illegal to circumvent that by agency or presidential decree".
‘Camp Fire’ forces evacuations in Northern California
Four hospital employees were briefly trapped in the basement and rescued by California Highway Patrol officers, Kinney said. Gavin Newsom requested a Presidential Emergency Declaration to aid with multiple fires burning in California.
President Donald Trump arrives to speak at a campaign rally, November 4, 2018, in Macon, Ga. More than 7,000 active duty troops could eventually be deployed, Defense Department officials said.
Mr. Trump has also threatened to end birthright citizenship through executive order, although he has yet to do so.
Those issues were not addressed by the regulations.
One senior administration official spoke to reporters in a news briefing on condition of anonymity.
Migrants pause to sleep and rest in Mexico City, Mexico, on their way to the United States border from South America. Only nine percent of those migrants seeking asylum, though, are ultimately granted asylum.
Claims have spiked in recent years, and there is a backlog of more than 800,000 cases pending in immigration court. Generally, only about 20 per cent of applicants are approved. The decision notes, however, that this is not to say that Trump cannot end DACA at all, but that in this case, the administration "acted based on an erroneous view of what the law required". But many migrants are unaware of that guidance, and official border crossings have grown clogged.
"Asylum-seekers have been left to camp out for days and weeks on bridges at the border, when they should be guaranteed a right to enter the country for a fair hearing".
POTUS initially revealed his administration's intentions last week during a speech at the White House in which he indicated that he was "finalizing a plan" to deny asylum claims from those who illegally enter the US.
It's unclear how many people en route to the USA will even make it to the border. They are now about 600 miles (965 kilometers) away. There's 5,000 people that were doing that in 20 - in 2008.