The US leader said social media was a “tremendous platform” that allowed him to bypass what he claimed was unfair media coverage and speak directly to voters.
Mr Trump regularly uses Twitter to mount vigorous attacks on political opponents, news outlets and people who have criticised him, often sending out posts in early-morning or late-evening flurries.
Even leaders of his own Republican Party have urged him to rein in his Twitter usage and Mr Trump admitted some friends have suggested his use of social media could damage him.
But he said: “I doubt I would be here if it weren’t for social media, to be honest with you.”
In an interview due to air on the Fox Business Network channel, the President added: “Tweeting is like a typewriter – when I put it out, you put it immediately on your show.
“When somebody says something about me, I am able to go bing, bing, bing and I take care of it. The other way, I would never be get the word out.”
His comments come after his rival for the presidency, Hillary Clinton, condemned his “dangerous” Twitter tirades.
The defeated Democrat told The Graham Norton Show that she “ignores” most of the President’s tweets but added: “The most dangerous thing he does is conduct diplomacy on Twitter. He is trading insults with Kim Jong-un, which is just like catnip for Kim Jong-un.”
Mr Trump’s tweets about North Korea have been widely seen as raising tensions amid the threat of nuclear war. In August, he threatened to unleash “fire and fury” upon the secretive nation before last month warning the North Korean regime “won’t be around much longer”, comments Pyongyang interpreted as “a clear declaration of war”.
Mr Trump’s tweets have also contained factual inaccuracies and personal attacks.
In March, he claimed Barack Obama had ordered Trump Tower in New York to be wiretapped – an allegation the former president denied and for which the Justice Department and FBI later said there was no evidence.
Last month, he lambasted NFL players who had kneeled in protest at police brutality and racial inequality.
Twitter was forced to defend its decision not to take down the latter post, which some saw as a violation of its terms of service, on the grounds it was “newsworthy” and in the public interest.
Earlier this month, Republic Senator Bob Corker warned Mr Trump’s provocative rhetoric risked setting the US “on the path to World War Three”.
Mr Trump had previously used Twitter to wage a personal war of words with Mr Corker.
“Senator Bob Corker ‘begged’ me to endorse him for re-election in Tennessee. I said ‘NO’ and he dropped out (said he could not win without my endorsement),” the President wrote after the senator criticised his response to white supremacist violence in Charlottesville.
Mr Corker said: “It’s a shame the White House has become an adult day care centre. Someone obviously missed their shift this morning.”
White House Chief of Staff John Kelly said last week he had been criticised for failing to control Mr Trump’s tweeting.
“I was not brought to this job to control anything but the flow of information to our president,” Mr Kelly added.
In July, Mr Trump was sued in federal court by seven people who he has blocked on Twitter.
The Justice Department said the suit should be dismissed, arguing it “rests on the unsupported and erroneous premise that the President’s Twitter account is a public forum for First Amendment purposes”.
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