In an interview with Fox News, Mr Spicer denied that there had been a rift in the White House following the appointment of Anthony Scaramucci as the administration’s communications chief.
Mr Spicer said he made his decision following talks at the White House with Mr Trump.
However, it has been reported in the American media that Mr Spicer had walked out because he objected to Mr Scaramucci’s appointment.
“The president wanted to add to the team. I thought it was in the best interests of the administration not to have too many cooks in the kitchen,” Mr Spicer told Fox News.
“I was increasingly disappointed how people in the media do their job, or rather don’t do their job,” he said.
“They are not there for the facts or pursuit of the truth, they are there to see how do I get on TV or become a YouTube star,” he added.
“More and more we are seeing it is about the clip and the click.”
Mr Spicer was ridiculed mercilessly by satirists especially on Saturday Night Live where he was impersonated by the actress Melissa McCarthy.
“There are times when it goes from funny to mean. You have to have a little bit of a thick skin if you are going to do this,” he said.
Appearing on the same programme, Reince Priebus, the White House Chief of Staff, denied that he was unhappy at Mr Scaramucci’s appointment.
“It is a good thing to start fresh. Sean gets to start fresh, Anthony gets to start fresh and the president gets to start fresh,” he told Fox News.
“It is time to get the president the credit he deserves. This is a good day to start that process.”