Federal courts have no authority to direct the executive branch to conduct foreign relations or engage with a foreign sovereign in a given matter, the Department of Justice said on Sunday in response to a motion for relief by attorneys for Kilmer Abrego Garcia, the Maryland man who was deported to El Salvador.

"Plaintiffs' additional relief runs headlong through this constitutional limit," said attorneys for the Department of Justice in a filing. "They ask this Court to order Defendants to make demands of the El Salvadoran government, dispatch personnel onto the soil of an independent, sovereign nation and send an aircraft into the airspace of a sovereign foreign nation to extract a citizen of that nation from its custody."

The requests by Abrego Garcia’s attorneys, the DOJ said, involve "interactions with a foreign sovereign -- and potential violations of that sovereignty."

"Plaintiffs invite this Court to 'exceed' its own 'authority' in the precise sort of way the Supreme Court cautioned against," DOJ added.

-ABC News' Laura Romero

President Donald Trump's administration has doubled down on its allegation that Kilmar Abrego Garcia is a member of MS-13 in the latest status update to the court.

Evan Katz, an official for Immigration and Customs Enforcement (ICE), acknowledged that while Abrego Garcia "should not have been" removed to El Salvador, Katz said that because of Abrego Garcia’s "membership in MS-13," he is not eligible for withholding of removal.

Abrego Garcia’s attorneys have denied this allegation.

Abrego Garcia -- despite being issued a 2019 court order barring his deportation to El Salvador, where his attorneys say he escaped political violence in 2011 -- was sent to that country's notorious CECOT mega-prison in March following what the government said was an "administrative error."

-ABC News' Laura Romero

President Donald Trump on Friday sent a presidential memorandum to Cabinet secretaries directing them to devise a plan to take jurisdiction over federal lands to combat illegal border crossings.

There are already about 10,000 troops stationed along the border supporting U.S. Customs and Border Protection, and this move could expand the role the troops play at the border.

The directive, sent to Defense Secretary Pete Hegseth, Interior Secretary Doug Burgum, Homeland Security Secretary Kristi Noem and Agriculture Secretary Brooke Rollins, will be first implemented on a "limited sector" of federal lands along the border, to be determined by Hegseth over the next 45 days.

The portions of border land occupied by the military might then expand "at any time," the memorandum says.

Border crossings have already descended to low levels since Trump took office and defined ending illegal immigration as a top priority, but officials have told ABC News that efforts at the border will continue until there is "total operational control."

-ABC News' Cheyenne Haslett

President Donald Trump weighed in Friday night into the legal battle over Kilmar Abrego Garcia.

The government faces a 5 p.m. deadline to provide the judge with more information about Garcia's whereabouts and efforts the United States is making to facilitate his return, following a Supreme Court order.

Trump told reporters he wasn't well versed in the case. However, he reiterated his respect for the Supreme Court.

"If the Supreme Court said bring somebody back, I would do that. I respect the Supreme Court," he said.

-ABC News' Katherine Faulders

The Supreme Court will require the Trump administration to facilitate the return of Kilmar Abrego Garcia, the Maryland man who was sent to El Salvador in error.

"The order properly requires the Government to 'facilitate' Garcia’s release from custody in El Salvador and to ensure that his case is handled as it would have been had he not been improperly sent to El Salvador," the Supreme Court's unsigned order stated. "The intended scope of the term 'effectuate' in the District Court’s order is, however, unclear, and may exceed the District Court’s authority. The District Court should clarify its directive, with due regard for the deference owed to the Executive Branch in the conduct of foreign affairs. For its part, the Government should be prepared to share what it can concerning the steps it has taken and the prospect of further steps."

There were no noted dissents.

Notably, the Supreme Court said the Trump administration's mistaken removal of Garcia to El Salvador was "illegal."

The court acknowledges that the status of Garcia as an alleged MS-13 gang member -- and potential threat to the American public -- remains contested. It also makes clear he is under an order to be removed from the U.S. — but expressly not to El Salvador.

The unsigned order does side with President Donald Trump's administration in believing the lower court's deadline to return Mr. Garcia was not acceptable. That deadline has now passed, and the issue is moot.

Justices Sonia Sotomayor, Elena Kagan and Ketanji Brown Jackson issued a statement agreeing with the Court's decision and reaffirming due process requirements owed all migrants in U.S. custody.

In response to the ruling, Garcia's attorney told ABC News "the rule of law prevailed."

“The Supreme Court upheld the District Judge’s order that the government has to bring Kilmar home," said Simon Sandoval-Moshenberg. "Now they need to stop wasting time and get moving."

-ABC News' Devin Dwyer and Laura Romero