Two state attorneys general have announced they've filed suit against U.S. President Donald Trump, alleging he violated the constitution by retaining ties to a sprawling global business empire.

The District of Columbia's Karl Racine and Maryland's Brian Frosh held a joint news conference Monday in Washington, confirming the suit filed in a Maryland court.

Racine and Frosh allege Trump's leases, properties and other business "entanglements" around the world pose a conflict of interest under a clause of the constitution.

"The president's conflicts of interest threaten our democracy," Frosh told journalists. "We cannot treat the president's ongoing violations of the constitution and his disregard of the rights of the American people as the new acceptable status quo."

Racine said the president has spoken about drawing a line between the presidency and his many businesses and properties, but he "has walked his promise back."

"We have a duty to enforce the law and that's why we are taking action today."

The White House did not immediately respond to requests for comment. The president called an earlier, similar lawsuit about the so-called emoluments clause of the constitution an issue "without merit, totally without merit."

The Trump Hotel in the nation's capital affects business in the Washington area and is part of the reason the lawsuit was filed, Frosh said earlier Monday.

'Subject to foreign influence'

"We have economic interests that are impacted, but the most salient factor is that when the president is subject to foreign influence, we have to be concerned about whether the actions he's taking — both at home and abroad — are the result of payments that he is receiving at the Trump Hotel, payments that he is receiving at Mar-a-Lago, payments that he is receiving at Trump Tower, payments that he is receiving in all of his other far-flung enterprises, and he brags about it."

The lawsuit also focuses on the fact that Trump chose to retain ownership of his company when he became president. Trump said he was shifting assets into a trust managed by his sons to eliminate potential conflicts of interests.

Demand for tax returns

If a federal judge allows the case to proceed, Racine and Frosh said they would demand copies of Trump's personal tax returns in court to gauge the extent of his foreign business dealings.

Trump and his lawyers have argued the emoluments clause does not cover fair-value transactions, such as hotel room payments and real estate sales.

Just days after Trump's inauguration in January, the government watchdog Citizens for Responsibility and Ethics in Washington also filed a federal lawsuit in the Southern District of New York. Since then, a restaurant group and two individuals in the hotel industry have joined as plaintiffs.

The Justice Department said Friday that those plaintiffs did not suffer in any way and had no standing to sue, and that it is unconstitutional to sue the president in his official capacity.