The Gateway Pundit, a provocative conservative blog, gained notice last year for its fervent pro-Trump coverage and its penchant for promoting false rumors about voter fraud and Hillary Clinton’s health that rocketed around right-wing websites.

Now the site will report on politics from a prominent perch: the White House.

The Trump administration has granted press credentials to Lucian B. Wintrich, the Washington correspondent for Gateway Pundit, to attend White House press briefings and ask questions of the press secretary, Sean M. Spicer.

Mr. Wintrich, an artist and writer who has collaborated with Milo Yiannopoulos, the polarizing editor at Breitbart News, attended President Trump’s news conference with the Canadian prime minister, Justin Trudeau, on Monday. He was joined by the owner of Gateway Pundit, Jim Hoft, who posted on Twitter, “President Trump just spoke about tossing criminal migrants and I wanted to stand up and cheer!!”

In a telephone interview from the West Wing, Mr. Wintrich, 28, said he would “be reporting far more fairly than a lot of the very left-wing outlets that are currently occupying the briefing room.” He added, “We will be doing a little trolling of the media in general here.”