WASHINGTON, April 6 (Xinhua) -- U.S. President Donald Trump signed a memo on Friday directing agencies to end "catch and release" practices that have allowed undocumented immigrants caught in the country to be released while their cases play out in court.

The memo orders the Department of Homeland Security in coordination with other agencies to submit a report to Trump within 45 days "detailing all measures that their respective departments have pursued or are pursuing to expeditiously end 'catch and release' practices."

White House press secretary Sarah Sanders characterized the practices as "dangerous."

"The safety and security of the American people is the President's highest priority, and he will keep his promise to protect our country and to ensure that our laws are respected," Sanders said in a statement.

She also said Trump continues to call on congressional Democrats to cease what she says "their staunch opposition to border security."

Trump has been publicly fuming over the U.S. immigration policy and border security situation, due to what he calls "weak" border laws. He has repeatedly called out Mexico over border security and stressed the need for a wall on the southern border.

On Thursday, Trump said that he wants to send between 2,000 and 4,000 National Guard members to the U.S.-Mexico border, after signing a proclamation directing the deployment.