Kellyanne Conway is seen as White House Press Secretary Sean Spicer speaks at a press briefing at the White House.

An independent government ethics office has urged the White House to probe and potentially discipline President Donald Trump's advisor Kellyanne Conway for comments she made supporting Ivanka Trump's clothing line.

In a letter released Tuesday, Office of Government Ethics Director Walter Shaub told deputy White House counsel Stefan Passantino that Conway appeared to breach a rule preventing her from using her position to promote private products. On Thursday, Conway said on Fox News to "go buy" the president's daughter's Nordstrom line, later adding that she would "give it a free commercial."

"These facts, if true, would establish a clear violation of the prohibition against misuse of position ... Therefore, I recommend that the White House investigates Ms. Conway's actions and consider taking disciplinary action against her," Shaub wrote.

The ethics office cannot discipline federal employees but is charged with recommending possible punishment. Therefore, the final decision on whether to discipline Conway comes down to the White House.

Press secretary Sean Spicer previously said that "Kellyanne has been counseled" for the remarks. However, Shaub said, "OGE has not yet received notification of any disciplinary or other corrective action" against Conway.