WASHINGTON - US President Donald Trump's administration on Tuesday announced new measures to expand its immigration crackdown by permitting more summary deportations of undocumented migrants.

The new rules allow immigration officials to pick up any undocumented migrant anywhere in the country and, if that person has been inside the United States less than 2 years, the officers can decide themselves to have them deported rather than have the case decided by an immigration judge.

Formerly, US Customs and Border Protection (CBP) and Immigration and Customs Enforcement (ICE) agents could arrest and summarily deport a migrant only if they were detained within 100 miles (160 kilometers) of the US border and were inside the country less than two weeks.

Cases for detainees not meeting those parameters would have to be processed in an immigration court.

"The effect of that change will be to enhance national security and public safety -- while reducing government costs -- by facilitating prompt immigration determinations," said a Department of Homeland Security notice published in the Federal Register.

"The new designation will enable DHS to address more effectively and efficiently the large volume of aliens who are present in the United States unlawfully," it said.

The Trump administration has been frustrated by the backlog at immigration courts which often allows detainees to disappear before their case is heard.

There are currently nearly one million pending cases, according to the website TracImmigration, and the average waiting time for a hearing is nearly 2 years.

The new rule could accelerate deportations from the estimated 10.5 million undocumented migrants living in the United States, almost two-thirds of them for more than 10 years, according to the Pew Research Center.

On Tuesday, Trump hit out at Guatemala, tweeting that he was considering halting remittances to or levying tariffs on the Central American country after its high court blocked a deal to designate it a "safe third country" earlier this month.

President Jimmy Morales said the court had interfered "without authority" to halt a deal that would have obliged Guatemala to keep migrants seeking asylum in the United States to stay within its borders as their claims were processed.