Border Patrol agents were given the edict by the Trump administration on President Trump’s first full day in office Tuesday. It represents a seismic shift from the “catch-and-release” open border days of the Biden administration, during which around 8 million illegal immigrants flooded into the country.

On Monday, appointments were canceled for people looking to cross the U.S. border just minutes after President Donald Trump took his oath of office.

The app has come under scrutiny in the past from Republicans, with some stating it has been used to hide illegal immigration.

The CBP One app has been highly popular, functioning as an online lottery system that grants appointments to 1,450 people daily at eight border crossings. These individuals enter the U.S. under immigration "parole," a presidential authority that Joe Biden has exercised more frequently than any other president since its creation in 1952.

"The first 100 days are going to be the most aggressive, change oriented policy proposals and procedures that we've ever seen," KOAT political expert Brian Sanderoff said.

President Trump on Monday signed an executive order ending birthright citizenship for children of illegal immigrants, likely setting off a legal battle in the courts.

The orders include declaring a national emergency to deploy military personnel to the border, suspending refugee resettlement and ending birthright citizenship.

Since CBP One app was fully rolled out in January 2023, more than half a million immigrants have been admitted into the United States.

President Donald Trump’s plans to curb immigration and beef up border security began taking effect soon after he was inaugurated Monday as he made good on campaign promises.

“If the US denies legal access or deports significant numbers of immigrants, Uganda stands to lose not only remittances but also the skills and knowledge contributed by these professionals. Under the new order, asylum applications can only begin in Mexico; individuals cannot enter the US and then apply for asylum,” he said.

President Donald Trump has promised swift action on immigration, asylum and border security as he takes office today.