FILE - In this May 13, 2016 file photo, the Nordstrom logo is displayed above the post where it trades on the floor of the New York Stock Exchange in New York. Nordstrom shares sunk after President Trump tweeted that the department store chain had treated his daughter Ivanka “so unfairly” when it announced last week that it would stop selling Ivanka Trump’s clothing and accessory line. (AP Photo/Richard Drew, File)
FILE - In this May 13, 2016 file photo, the Nordstrom logo is displayed above the post where it trades on the floor of the New York Stock Exchange in New York. Nordstrom shares sunk after President Trump tweeted that the department store chain had treated his daughter Ivanka “so unfairly” when it announced last week that it would stop selling Ivanka Trump’s clothing and accessory line. (AP Photo/Richard Drew, File) Credit: Richard Drew

New York — Where the White House saw a father standing up for his daughter, an ethics expert saw an implicit threat.

President Donald Trump lashed out on Wednesday at Nordstrom, the latest company to draw his Twitter attention, saying the department store chain that decided to stop selling his daughter’s clothing and accessory line has treated her “so unfairly.”

Though Trump has tweeted in the past about companies such as the U.S. automakers, Boeing and Carrier, his action drew a rebuke from ethics experts saying the fact that this one was about a business run by his daughter raised conflict-of-interest concerns. Trump’s tweet follows revelations that first lady Melania Trump expected to develop “multi-million dollar business relationships” tied to her presence in the White House, according to a suit she filed.

In the tweet, Trump said, “My daughter Ivanka has been treated so unfairly by @Nordstrom. She is a great person — always pushing me to do the right thing! Terrible!” Posted first on his personal account, it was re-tweeted more than 6,000 times in less than an hour. It was also retweeted by the official @POTUS account.

Trump’s presidency has raised unprecedented concerns about ethical conflicts. His plan to separate himself from his sprawling real estate business has been criticized by ethics experts, who say it doesn’t do enough to make sure that Trump won’t make decisions to personally benefit himself, his family or his company. The first lady has yet to step away from her companies that manage her royalties from her namesake products, business documents show.

Kathleen Clark, a government ethics expert, said the Nordstrom tweet is problematic because other retailers may think twice now about dropping the Ivanka Trump brand for fear of getting criticized publicly by the president. She said it was especially disturbing that Trump retweeted his message on the official White House account.

“The implicit threat was that he will use whatever authority he has to retaliate against Nordstrom, or anyone who crosses his interest,” said Clark, a law professor at Washington University in St. Louis.

Clark defended the president’s right to use his personal Twitter account to express his views, noting that government workers recently set up alt-EPA accounts to criticize the president’s policies. “A government employee, even a president, is allowed to tweet in his personal capacity.”

Trump has feuded with several consumer brands before and after winning the presidency. After Macy’s dropped his line of ties and shirts in 2015 over his comments about immigrants, Trump singled Macy’s out for having a tough holiday season. “Good news, disloyal @Macy’s stock is in a total free fall. Don’t shop there for Christmas,” he tweeted.