"The fake media tried to stop us from going to the White House, but I'm President and they're not. We won, and they lost," Trump said during the Celebrate Freedom Rally at the Kennedy Center in Washington D.C. on Saturday.
"The dishonest media will never keep us from accomplishing our objections on behalf of our great American people. It will never happen. Their agenda is not your agenda, you've been saying it," he said.
The President continued his attack on Joe Scarborough and Mika Brzezinski, the hosts of MSNBC's "Morning Joe", two days after saying on Twitter that Brzezinski had been "bleeding badly from a face-lift" during a social event last year.
Before taking off from Bedminster, New Jersey, to travel to the event in Washington, Trump tweeted in defence of his use of the social media.
"My use of social media is not Presidential - it's MODERN DAY PRESIDENTIAL. Make America Great Again!" he tweeted.
On Saturday, he added: "Crazy Joe Scarborough and dumb as a rock Mika are not bad people, but their low rated show is dominated by their NBC bosses. Too bad!"
Trump also continued his blistering criticism of CNN in a series of tweets. He wrote: "I am extremely pleased to see that @CNN has finally been exposed as #FakeNews and garbage journalism. It's about time!"
"I am thinking about changing the name #FakeNews CNN to #FraudNewsCNN!," another of his tweet said.
Apart from slamming the media at the event, Trump reiterated his administration's commitment to honouring and caring for the nation's veterans, the Hill reported.
He also touted the Veterans Accountability Act, which he said would allow the Department of Veterans Affairs to more easily utter the words "you're fired" to under-performing employees.
On religious liberty, Trump pledged to the largely Evangelical audience that he would never forget them and said to cheers, "We're going to start saying 'Merry Christmas' again" in the US".
"My administration will always support and defend religious liberty. We don't want to see God forced out of the public square, driven out of our schools or pushed out of our civic life, we want to see prayers before football games if they want to give prayers," he said.
Trump said he's "very happy and very proud" of following through on a campaign promise to repeal the Johnson Amendment, which prohibits non-profits like churches from endorsing or opposing political candidates.