Donald Trump has threatened to walk out of future press briefings if reporters do not act with 'decorum'.
The US president was speaking after a Washington DC court ordered the White House to return CNN reporter Jim Acosta's press pass after it was revoked by the US Secret Service.
Acosta's press pass was taken after he clashed with the president during a news conference earlier this month.
Trump played down the ruling, saying it wasn't "a big deal".
But, he said, "people have to behave", adding his staff were "writing up rules and regulations" for the press to abide by, including sticking to the agreed number of questions.
"If they don't listen to the rules and regulations we'll end up back in court and will win," Trump said. "But more importantly, we'll just leave, and then you won't be very happy."
"You can't take three questions and four questions and just stand up and not sit down," he added. "Decorum. You have to practice decorum."
'A great day'
Speaking outside the court earlier in the day, Acosta praised the decision and told reporters "let's go back to work".
The judge said the White House decision likely violated the journalist's right to due process and freedom of speech, reports the BBC.
The ruling forces the White House press office to temporarily return Acosta's "hard pass", the credential that allows reporters easy access to the White House and other presidential events.
Acosta's lawyer called the ruling "a great day for the first amendment and journalism".
How did the row begin?
Acosta was barred from entering the White House a day after he had a heated exchange with President Trump during a news conference on 8 November.
A White House intern tried to take the microphone from Acosta as he attempted to ask the president a follow-up question.
In a statement Sanders claimed that he had put "his hands on a young woman" during the exchange, during which Trump called the reporter "a rude, terrible person".
CNN sued to have Acosta's pass restored, and their lawsuit was joined by other media groups, including conservative-leaning Fox News.
