President Trump defended his decision on Tuesday to give Congress six months to determine how to address the problem of illegal immigrants who arrived as minors "with heart and compassion," while his administration phases out the Obama-era Deferred Action for Childhood Arrivals program.

"In the best interests of our country, and in keeping with the obligations of my office, the Department of Homeland Security will begin an orderly transition and wind-down of DACA, one that provides minimum disruption," Trump announced in a statement.

The DACA program, which former President Barack Obama created by executive memorandum in 2012, currently shields about 800,000 illegal immigrants between the ages of 15 and 36 from the threat of deportation. More than 200,000 DACA beneficiaries are set to lose their legal status by the end of 2017 if Congress fails to approve legislation that would establish a path to permanent legal status or citizenship for such individuals, DHS said Tuesday.

"Congress now has the opportunity to advance responsible immigration reform that puts American jobs and American safety first," Trump said. "We will resolve the DACA issue with heart and compassion – but through the lawful Democratic process – while at the same time ensuring that any immigration reform we adopt provides enduring benefits for the American citizens we were elected to serve."

The president's decision on DACA comes in response to an informal deadline imposed by Texas Attorney General Ken Paxton, who had threatened to sue to his administration over the constitutionality of the program if it remained in place by Sept. 5.

"The Attorney General of the United States, the Attorneys General of many states, and virtually all other top legal experts have advised that the program is unlawful and unconstitutional and cannot be successfully defended in court," Trump said.

The DACA program will be completely phased out by March 5, 2018, granting Congress a narrow six-month window to determine how to handle current beneficiaries of the program and those whose legal status will expire before the end of the year.