WASHINGTON - President Donald Trump said Tuesday that America's current immigration system weakens national security, as his administration sought Supreme Court backing to lift protections shielding 700,000 "Dreamer" immigrants from deportation.

Days after Trump sparked an international uproar by reportedly complaining about immigration from "shithole" countries, his administration sought to refocus the debate by tying a series of current immigration programs to terror threats.

A new report from the Justice and Homeland Security Departments said that nearly three-fourths of the 549 international terror-related convictions in US courts since the September 11 attacks in 2001 involved foreign-born individuals, including 148 granted citizenship after arriving in the United States. It also said it had blocked many hundreds more potential terrorists who tried to enter the country both legally and illegally.

Trump tweeted out a link to the report Tuesday evening, in support of White House efforts to end programs like the green card lottery and family-based migration.

"We have submitted to Congress a list of resources and reforms. We need to keep America safe, including moving away from a random chain migration and lottery system, to one that is merit-based," he said.

Attorney General Jeff Sessions unveiled the report five days after Trump rejected a bipartisan deal that aimed to reform some immigration programs, partly fund a Mexican border wall, and guarantee the status of the "Dreamers" - immigrants brought to the United States illegally as children.

Sessions described the data as "only the tip of the iceberg."

"We currently have terrorism-related investigations against thousands of people in the United States, including hundreds of people who came here as refugees."

"This report reveals an indisputable sobering reality - our immigration system has undermined our national security and public safety," he said.

Trump lashed out last week at the US judicial system as "broken and unfair" after a judge blocked his decision to scrap the program that has protected the so-called Dreamers from deportation since 2012, known as Deferred Action for Childhood Arrivals (DACA).

His Justice Department courted further controversy Tuesday when it announced it would appeal directly to the Supreme Court the San Francisco judge's challenge to Trump's order to end DACA.