The New York Times on Wednesday published a blistering op-ed article by an anonymous author, described only as "a senior official in the Trump administration," who said there was a secret "resistance" inside the White House.

The editor of the op-ed article said in an interview released Thursday that he had spoken to the author since its publication.

The editor also said that he was in direct contact with the author before publication and that extensive research was done to fully confirm their identity.

The author of an anonymous op-ed article published in The New York Times on Wednesday saying that some members of the Trump administration were part of a secret "resistance" working to undermine the president is still in contact with the newspaper, its op-ed editor said Thursday.

The Times described the author only as "a senior official in the Trump administration." The op-ed editor, Jim Dao, spoke on Thursday's episode of the newspaper's podcast "The Daily," where the host Michael Barbaro asked, "Have you heard from the writer since the piece was published?"

"I have," Dao responded.

When asked by Barbaro whether the writer was surprised by the reaction to and popularity of the column, Dao said, "I'm not quite sure how surprised they were."

But Dao said that he was surprised by the impact of the column and that he perhaps "should have been more nervous" in light of its popularity.

"I thought it would be well-read," Dao said. "I had no idea."

Dao also said that he was in direct contact with the author before the column was published on Wednesday but that he was originally connected through an intermediary.

"I did then have direct communication with the writer," Dao said.

Dao said he had to get to a point where he was "100% confident that they were who they are," a process that he said involved research and background checks.

"Based on those conversations," Dao said, he "came away feeling totally confident that this was the official in the Trump administration that they claimed they were."

Trump has criticized the anonymity of the article, calling the author "gutless." Dao said in the interview that The Times' opinion section rarely granted anonymity but had done so when the author would be in danger, personally or professionally, if their identity were revealed.

Dao said he couldn't imagine any circumstances in which The Times' opinion section would identify the author.