Three US media outlets have requested an emergency court hearing, accusing the White House of having "repeatedly violated" a judge's order to restore their access in a stand-off with President Donald Trump.
Employees from CNN, Politico and MS Now reported being denied entry on Thursday morning, with some having their credentials confiscated, while others were granted access.
Judge Timothy Kelly ruled in the early hours of Thursday that Trump's ban on the outlets should be temporarily lifted because it "likely violated their constitutional due process rights".
Trump initially said he banned the outlets because of "fake news". The White House later cited national security.
It was unclear whether the refusal to admit some reporters on Thursday morning was because of an administrative lag as the White House potentially worked to comply with the judge's order.
The standoff was expected to impact TV coverage as Trump welcomes Chinese President Xi Jinping to the White House on Thursday morning ahead of a state dinner.
CNN said some of their journalists had been denied entry, including senior White House reporter Betsy Klein. But a producer was allowed to enter, the outlet reported.
Politico said one of its reporters was denied access to the White House and had his press credentials confiscated.
MS NOW reported that its White House reporter Laura Barrón-López and a producer were barred and had their passes taken, but another MS NOW producer was allowed in.
The White House is yet to comment on the ruling, and lawyers acting for the president may take further legal action.
Trump first announced last Friday he was barring the three major US media outlets - CNN, MS Now and Politico - from the White House, accusing them of writing "fiction or lies" about his administration.
By Saturday morning, each outlet reported that they were denied entry to the White House grounds and that their press badges were confiscated.
All three outlets spoke out against the ban, accusing the Trump administration of violating their constitutional rights.
In a joint statement on Monday, they said they were pursuing legal action to "defend the principle that the government does not decide what the press reports".
Most other major media outlets have stood behind the three outlets in their fight against Trump's ban, with TV networks including Fox News, NBC, CBS and ABC suspending their televised coverage of the White House in solidarity.
And more than 50 media organisations across the ideological spectrum filed an amicus brief in support of the lawsuit, including Fox News, The New York Times, The Washington Post and The Wall Street Journal.
There have been previous instances of administrations attempting to limit certain outlets' access.
The Obama administration tried to exclude Fox News from participating in a specific press pool interview with an administration official in 2009.
But after objections from the other four networks in the pool, Fox News was allowed in.