@RealDonaldTrump has become an integral part of his presidency and is often the place where the world gets the first glimpse of his thoughts on a particular subject.
President Trump has also used the account to attack his critics, but has blocked those who disagree with his views.
Among those who have been prevented from directly responding to his tweets are said to be novelist Stephen King, comedian Rosie O’Donnell and model Chrissy Teigen.
But a New York judge has ruled that the president’s account, and those of other government officials, are public forums and that blocking Twitter users for their views violated their right to free speech under the First Amendment of Constitution.
The decision by US District Judge Naomi Reice Buchwald was a result of lawsuits by several Twitter users who had been blocked from Mr Trump’s account.
She rejected the Department of Justice’s argument that the president’s own First Amendment rights allowed him to block people with whom he did not wish to interact.
Judge Buchwald said: “While we must recognise, and are sensitive to, the presidents personal First Amendment rights, he cannot exercise those rights in a way that infringes the corresponding First Amendment rights of those who have criticised him.”
She added that he could “mute” users, meaning he would not see their tweets while they could still respond to his, without violating their free speech rights.
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Among those who brought the case was Maryland university professor Philip Cohen, who was blocked last year after posting an image of the president with words “corrupt, incompetent authoritarian”.
He said the ruling “increases my faith in the system a little” but added that he had yet to be unblocked.