Deputy national security adviser Matt Pottinger is the latest in a series of resignations of senior White House administration staff, according to CNN.
Mr Pottinger had reportedly intended to resign on election day, but was persuaded to stay on by national security adviser Robert O'Brien.
Mr O'Brien, who is also rumoured to be considering resignation, has signalled his unhappiness over recent violence on Capitol Hill.
Expressing outrage on social media following the violence on Wednesday evening, Mr O'Brien wrote: "What the mob did to our Senate Chamber today was an utter disgrace."
Mr O'Brien later retweeted a post by conservative commentator Andy Ngo, who called for the arrest of "Trump supporters" vandalising parts of the Capitol building.
This follows a growing chorus of dissent among President Donald Trump's most fervent supporters, angered by what they see as incitement by the president, who continues to insist the US elections were fraudulently 'stolen' by president-elect Joe Biden.
Late on Wednesday, two top aides to US first lady Melania Trump also resigned after the Capitol Hill riots.
Stephanie Grisham resigned as chief of staff to the first lady, the White House social secretary, Rickie Niceta, also resigned, as did a deputy White House press secretary, Sarah Matthews.
"It has been an honour to serve the country in the White House. I am very proud to have been a part of Mrs Trump’s mission to help children everywhere and proud of the many accomplishments of this administration," said Mr Grisham in a statement.
Ms Grisham, who spent a year as White House press secretary before becoming chief of staff to the first lady, did not say whether her resignation was in reaction to the violence in the nation's capital, but a source familiar with her decision said the violence was the last straw for her.
Mr O'Brien said in a statement earlier Wednesday: "I just spoke with Vice President Pence. I am proud to serve with him."
There was also chatter inside the White House that deputy chief of staff Chris Liddell might resign, a source said.
The mounting anger among those close to Mr Trump began after the president continued to push unfounded claims that the US election was marred by large-scale fraud. On Thursday, Senator Lyndsey Graham said that Mr Trump's continued campaign to overturn results had pushed him to part ways with the president.
"Trump and I, we had a hell of a journey. I hate it being this way … all I can say is count me out. Enough is enough. I tried to be helpful," he remarked.
Injuries were reported and one woman was killed in the melee at the Capitol, as Trump supporters responded to the president's call to protest his loss in November's presidential election to Democrat Joe Biden. Mr Trump has repeatedly and baselessly claimed the election was marred by fraudulent voting.