Sanders said the suspension of his press credentials stemmed from his "placing his hands on a young woman just trying to do her job as a White House intern".
In another video of the encounter tweeted by Sarah Burris, an editor at the left-leaning political blog Raw Story, the footage has been slowed down and annotated to show the four times the White House intern touches Acosta while trying to take the microphone.
A White House staff member reaches for the microphone held by CNN's Jim Acosta during a news conference at the White House in Washington, November 7, 2018.
White House correspondent Jim Acosta.
Acosta tweeted that Sanders' statement that he put his hands on the aide was "a lie".
The episode will reignite fears that Mr Trump has scant regard for press freedom and is intent on limiting space for critical coverage.
Acosta pressed him on why he called the migrant caravan making its way from Central America to the USA border an invasion.
Trump wanted to move onto another reporter, but Acosta wouldn't give up the microphone when an aide sought to tug it away from him.
In an earlier statement, CNN said the president had "gone too far" during his clash with Mr Acosta - describing his "ongoing attacks on the press" as "dangerous and disturbingly un-American".
"I don't know why you would say that", President Trump responded.
"Not you. Your organisation is bad", Trump said. The White House has accused him of provoking confrontations, and he, in turn, has become a favorite target of insults lobbed by Trump's supporters, particularly during the president's raucous rallies.
The decision to expel Acosta came just hours after confirmation that the Republican Party had lost control of the US House of Representatives on Wednesday.
So what is it about CNN's chief White House correspondent that Trump just can't stand?
The White House Correspondent's Association issued a statement saying it "strongly objects to the Trump Administration's decision to use US Secret Service security credentials as a tool to punish a reporter with whom it has a hard relationship".
"I understand", Mr Alexander said, attempting to ask a question.
The claim has been described by Acosta as a "lie".
While Trump appeared comfortable and relaxed, he grew upset quickly after Acosta was called upon and refused to let other reporters speak after Trump answered his four questions.
Craig Aaron of the activist group Free Press called Trump's actions "a direct and unsafe attack on the public's rights to hold their leaders accountable" and called for "a unified stand" by the press corps. You and I disagree on this, ' Trump said.
"They are not only unsafe, they are disturbingly un-American", the network said.
In a statement Wednesday night, CNN said that Sanders "provided fraudulent accusations and cited an incident that never happened".
At a combative, lengthy news conference Wednesday, U.S. President Donald Trump congratulated himself for achieving what he termed a "tremendous success" in the previous day's midterm elections.