The Trump administration on Monday stonewalled a federal judge seeking answers about whether the government had violated his order by deporting more than 200 people over the weekend, including those officials identified as members of a Venezuelan criminal gang.

The hearing in Federal District Court in Washington escalated a conflict between the White House and the courts that threatened to become a constitutional crisis.

A Justice Department lawyer refused to answer any detailed questions about the deportation flights to El Salvador, arguing that President Trump had broad authority to remove immigrants from the United States with little to no due process under an obscure wartime law known as the Alien Enemies Act of 1798.

The tense back-and-forth in court between the judge, James E. Boasberg, and the Justice Department lawyer, Abhishek Kambli, left open the possibility of further conflict down the road. Judge Boasberg directed Mr. Kambli to certify in writing by noon on Tuesday — under seal if needed — that no immigrants were removed after his written order went into effect, a piece of information that will be crucial as the judge seeks to determine whether the Trump administration flouted his authority.

The legal battle over the removal of the immigrants was the latest — and perhaps most serious — flashpoint yet between federal courts, which have sought to curb many of Mr. Trump’s recent executive actions, and an administration that has repeatedly come close to openly refusing to comply with judicial orders.

Earlier Monday, Mr. Trump’s so-called border czar, Tom Homan, made defiant remarks on television, indicating that the administration planned to continue such deportations despite the court’s order — an action that could pit one of the coequal branches of the government against another.