New York's attorney general issued a cease and desist notice to Donald Trump's foundation Monday on the grounds that it was violating the law by accepting donations without proper state certification.

James Sheehan, the chief of the A.G. office's Charity Bureau, wrote in a "Notice of Violation" that the Trump Foundation must "immediately" halt fundraising activities in the state. According to the notice, the Trump Foundation is in violation of New York's Executive Law, "which requires charitable organizations that solicit contributions in New York State to register with the Charities Bureau."

"The Trump Foundation must immediately cease soliciting contributions or engaging in any other fundraising activities in New York," Sheehan wrote in the notice, which was sent to the Trump Foundation on Friday.

The notice was also sent one day after the Washington Post reported that the foundation was not properly registered with the state and, therefore, unable to accept public donations. The foundation has been funded by public donations since 2008, when Trump himself made his last contribution.

Attorney General Eric Schneiderman, a Democrat, ordered the Trump Foundation to deliver the proper paperwork to the state within 15 days. The notice added that if this step is not taken and solicitations are not discontinued, the Charities Bureau will consider the actions "continuing fraud" against the state.

In a statement, Trump spokesman Hope Hicks pointed to "political motives" behind the move by Schneiderman, who is an outspoken backer of former Secretary of State Hillary Clinton, adding that the foundation will cooperate fully with the investigation.

"While we remain very concerned about the political motives behind AG Schneiderman's investigation, the Trump Foundation nevertheless intends to cooperate fully with the investigation," Hicks said. "Because this is an ongoing legal matter, the Trump Foundation will not comment further at this time."

Schneiderman was previously criticized for his handling of an investigation into what Exxon Mobil knew about the science of global warming and climate change.

In recent months, questions have surrounded the foundation. The foundation came under increased scrutiny after it was revealed that Trump made a $25,000 donation to Florida Attorney General Pam Bondi as her office was looking into Trump University. Both Trump and Bondi have denied any wrongdoing in the matter. Bondi has since endorsed Trump's presidential bid.

Trump has also come under fire for using foundation funds to purchase two portraits of himself, as well as a signed helmet by former NFL quarterback Tim Tebow.