Acosta tweeted Wednesday night: "This is a lie".
Footage of the incident shows the intern tried to reach under Acosta's arm to take the mic from him, and his arm came down on hers as he continued to try asking his question of Trump.
Trump interrupted Acosta. "I'm not concerned about anything with the Russian investigation because it's a hoax".
In a statement announcing the disciplinary measure Wednesday evening, Sanders said, "President Trump believes in a free press and expects and welcomes tough questions of him and his administration".
"It was a pretty surreal experience", Acosta, who has covered the White House for five years, said of the situation.
However, Mr Acosta refused to give it up as he attempted to ask the president a further question. "It's a very awful thing you said to me".
You and I disagree on this, ' Trump said.
"You run CNN. And if you did it well, your ratings will be much higher".
"The White House is suspending the hard pass of the reporter involved until further notice", said White House spokesperson Sarah Sanders hours later, referring to Acosta, who then tweeted that he had been denied White House entry.
The video is below; the microphone grab is at the:18 mark.
'The way you treat Sarah Huckabee is awful, ' he said. Trump told Acosta "That's enough!" as the reporter tried to ask another question, moving on to the topic of the Russian Federation investigation.
"A free press is vital to democracy, and we stand behind Jim Acosta and his fellow journalists everywhere". The way you treat other people is terrible. "I've travelled with him and watched him", Mr Alexander said.
These weren't the only reporters to grate on the president at this press conference, though. "Even if President Trump doesn't intend it, some see him as directly appealing to the racists", she wrote.
"They are not only unsafe, they are disturbingly un-American", the network said. "It's so sad", Trump said.
Sanders claimed the incident proved Trump's "support for a free press". "Surely you don't trust InfoWars.?" he said on Twitter.
The president began the wide-ranging press conference with a focus on the election results, but it soon devolved into brazen and shocking media attacks that appeared created to frustrate and enrage the president.