New York sues to dissolve Trump Foundation

President Donald Trump has attacked New York's attorney-general for suing his charitable foundation

US President Donald Trump has attacked "sleazy New York Democrats" after the state's attorney general sued him and his namesake foundation, adding he would not settle the case.

New York's Attorney General Barbara Underwood is suing Trump and the Donald J. Trump Foundation, saying the nonprofit should be dissolved after more than a decade of illegal conduct, including support for Trump's 2016 US presidential campaign.

Underwood accused the foundation and its directors of conducting "extensive unlawful political coordination" with the campaign, and "repeated and wilful self-dealing" to benefit Trump's personal and business interests.

"The Trump Foundation was little more than a chequebook for payments from Mr. Trump or his businesses to non-profits, regardless of their purpose of legality," Underwood said in a statement on Thursday. "That is not how private foundations should function."

"The sleazy New York Democrats, and their now disgraced (and run out of town) A.G. Eric Schneiderman, are doing everything they can to sue me on a foundation that took in $18,800,000 and gave out to charity more money than it took in, $19,200,000. I won't settle this case!" Trump wrote on Twitter.

Trump's children were also named as defendants in the attorney general's petition, filed with the New York State Supreme Court in Manhattan.

New York is also seeking $US2.8 million of restitution plus penalties, a 10-year ban on Trump serving as a director of a New York non-profit, and one-year bans for his children Donald Jr, Eric and Ivanka.