The judge hearing a challenge to President Trump’s attempt to block three news outlets from the White House heard arguments on Wednesday before announcing he would issue his ruling later. The outlets — CNN, MS NOW and Politico — will remain barred while Judge Timothy J. Kelly of Federal District Court in Washington weighs the arguments.

Mr. Trump’s statements about the ban made him “our lead witness,” a lawyer for the organizations told the judge. A Justice Department lawyer, Michael Velchik, argued the ban was imposed on national security grounds. The judge, nominated by Mr. Trump in 2017, previously ruled against the president in a similar dispute with CNN in 2018.

Other news organizations responded with acts of support. The TV pool — ABC News, CBS News, NBC News, Fox News and CNN — suspended shared coverage of Mr. Trump, and outlets including The New York Times temporarily withheld publication of pool photos of his events.

The media companies argue the president banned them based on distaste for their journalism. Theodore J. Boutrous, their lawyer, suggested national security concerns were raised as a late justification. The judge took the arguments under advisement.