An investigation is just beginning into the fatal plane crash over the Potomac River in Washington, with no cause determined yet by the National Transportation Safety Board.

President Donald Trump, though, was quick to try to assign blame on Thursday as he gave a press conference at the White House while recovery crews navigated the icy waters searching for victims.

“We do not know what led to this crash, but we have some very strong opinions,” he said.

Trump first claimed, without evidence, that diversity, equity and inclusion initiatives under Democratic presidents could be a factor. He later doubled down on the unsubstantiated claim while he signed executive orders in the Oval Office.

Trump also suggested the helicopter pilots navigating the U.S. Army Black Hawk should have moved out of the way but at one point said warnings to the crew were given “very late.”

On Friday, he continued to question the chopper’s movement as it appeared to be flying above the mandated 200 feet. “That’s not really too complicated to understand, is it???” he wrote on his social media platform Truth Social.

Leading the investigation into the crash is the NTSB, with a preliminary report due in 30 days but a final report on probable cause not likely for at least a year.

NTSB member Todd Inman, during an appearance on “Good Morning America” on Friday, said it is far too early to make a determination.

“The only conclusion I know is last night we met with several hundred family members who lost their loved ones in the Potomac,” he said. “We don’t need that to happen anymore. … We’re going to find out what happened, and we’re going to try to stop it from happening again.”

Trump accused former President Joe Biden and former President Barack Obama of hiring air traffic controllers based on diversity goals.

“I put safety first — Obama, Biden and the Democrats put policy first, and they put politics at a level that nobody’s ever seen,” Trump claimed at Thursday’s news conference.

When pressed by ABC News Chief White House Correspondent Mary Bruce what proof he had that the crash was caused by DEI efforts, Trump responded: “It just could have been.”

DEI or any similar program does not apply to hiring for air traffic control, which requires rigorous health examinations and a multiyear training process. Applicants must pass a medical exam, an aptitude test and a psychological test that is more stringent than that required of a pilot, said Chris Wilbanks, FAA deputy vice president of safety and technical training.

Trump pointed to a New York Post article as he accused Democrats of pushing to hire people with severe mental disabilities at the Federal Aviation Administration. But the diversity language referenced in the article was on the FAA website during the entirety of Trump’s first term and has been on the site for more than a decade, according to Snopes.

Trump’s attacks, though, are in line with his agenda to dismantle DEI from the federal government. In his first week in office, he signed multiple orders to place federal employees working on DEI on administrative leave and to remove DEI efforts from the Pentagon.

Democrats pushed back on Trump’s claims about the crash.

“Listen, it’s one thing for internet pundits to spew off conspiracy theories. It’s another for the president of the United States to throw out idle speculation as bodies are still being recovered and families still being notified,” Senate Minority Leader Chuck Schumer, D-N.Y., said on Thursday. “It just turns your stomach.”

Pete Buttigieg, Biden’s transportation secretary and another target of Trump’s criticism in the wake of the crash, called Trump’s comments “despicable.”

“President Trump now oversees the military and the FAA,” Buttigieg wrote in a social media post. “One of his first acts was to fire and suspend some of the key personnel who helped keep our skies safe. Time for the President to show actual leadership and explain what he will do to prevent this from happening again.”

ABC News’ Selina Wang, Benjamin Siegel, Sam Sweeney, Fritz Farrow and Hannah Demissie contributed to this report.