"US law is crystal clear that asylum seekers have the right to lodge asylum claims regardless of where they enter the country, and President Trump can not change the law on a whim", said Bill Frelick, Refugee Rights director at Human Rights Watch.
Days later, the Supreme Court upheld the president's controversial travel ban against people from several Muslim majority countries.
"Those who enter the country between ports are knowingly and voluntarily breaking the law", one unnamed official told reporters, the Post reported. U.S law states that any individual can seek asylum, whether or not they are at an official point of entry.
The new rule comes as a so-called caravan of migrants from Central America travels north by foot through Mexico to the us border.
Administration officials said those denied asylum under the proclamation may be eligible for similar forms of protection if they fear returning to their countries, though they would be subject to a tougher threshold.
Migrants in serious fear of persecution were considered refugees under worldwide law. These are people who are referred for interviews.
Those seeking political or other kinds of asylum - almost all of them coming from impoverished and violent crime-plagued countries of Central America - will be heard exclusively at the border crossings, administration officials told journalists.
A number of lower courts had originally deemed the measure unconstitutional.
Officials have turned away asylum seekers at border crossings because of overcrowding, telling them to return later.
The goal of the new policy, according to a document the administration posted Thursday, is to push migrants toward official ports of entry where they can be processed in a "controlled, orderly, and lawful manner". Only nine percent of those migrants seeking asylum, though, are ultimately granted asylum.
Those delays increase the chances that caravan members could attempt to cross illegally by fording the Rio Grande or trekking through the desert to set foot on USA soil and surrender to Border Patrol agents.
Trump has long said those seeking asylum should come through legal ports of entry.
That status does not give foreigners a path to a green card or citizenship, and instead functions as a kind of provisional suspension of the deportation process, revocable at any time. Claims have spiked in recent years, and there is a backlog of more than 800,000 cases pending in immigration court.
The interim final rule to limit asylum proposed on November 8, 2018, by the Trump Administration is the latest attempt to shut American doors to people fleeing persecution and violence, Human Rights Watch said today. "They clearly and explicitly meant to make asylum available to anyone who reaches the United States".
"It is illegal to circumvent that - by agency or presidential decree".
Trump said he would allow the program to expire, after Texas and other states threatened to sue to force an end to protections.
Well, the president is invoking national emergency powers, national security powers, because he sees immigration as a national security, a crisis, really. As such, it is likely to be challenged in federal courts.