US President Donald Trump speaks during the National Rifle Association Annual Meeting on April 26, 2019, at Lucas Oil Stadium in Indianapolis, Indiana.

"The NRA should leave and fight from the outside of this very difficult to deal with (unfair) State!" the president wrote in a subsequent tweet.

The president's comments follow the news that New York Attorney General Letitia James opened an investigation into the group, including ordering the preservation of internal documents. James said during her campaign that she intended to look into the New York-chartered group's nonprofit status.

The president also chided the group for a leadership fight that has played out in public in recent days, saying the NRA "must get its act together quickly, stop the internal fighting, & get back to GREATNESS - FAST!"

President Donald Trump said Monday the National Rifle Association is "under siege by Cuomo," days after New York's attorney general opened an inquiry into the gun rights lobbying organization.

The chaos gripping the NRA spilled into public view last week in the midst of its annual convention in Indiana, where both Trump and Vice President Mike Pence delivered remarks.

Shortly after Trump spoke to the group, The Wall Street Journal reported that the NRA's longtime leader, Wayne LaPierre, had informed the board that he was being extorted and pressured to resign by retired Lt. Col. Oliver North, another top NRA official.

LaPierre wrote in a letter to the organization's board that North was threatening to make public "destructive" embarrassing information about him and the NRA's financial dealings.



On Saturday, North announced that he will not serve a second term as the group's president. The Iran-Contra figure wrote in a letter to NRA members on Saturday that the organization faced a "clear crisis" and that, if the allegations about financial mismanagement were true, "the NRA's nonprofit status is threatened."

Trump tweet two

James' office has gone after the president's own nonprofit, the Donald J. Trump Foundation. The foundation agreed to dissolve under judicial supervision last year after state's previous attorney general, Barbara Underwood, accused it of "a shocking pattern of illegality," and said her office would pursue further investigations.

In a March filing, James wrote that the foundation broke "some of the most basic laws" related to private foundations. Her office is seeking nearly $3 million in restitution from the foundation.

Trump foundation attorneys have denied the allegations and accused officials in the heavily Democratic state of having political motivations.

New York Gov. Andrew Cuomo, a Democrat, recently opened up his formidable financial support network to Democratic presidential contender Joe Biden, the former vice president, who is the early front runner in the primary race that will determine which candidate faces off against Trump in 2020.

In a statement, Cuomo fired back against the president's tweet.

"Unlike you, President Trump, New York is not afraid to stand up to the NRA. I will continue to fight for the children of this state. As for the NRA, we'll remember them in our thoughts and prayers," he said.

And James's office said in a statement that "we will follow the facts wherever they may lead."

"We wish the President would share our respect for the law," the statement said.

-- CNBC's Kevin Breuninger contributed to this report.