House Democrats on Monday demanded government records related to the federal response to the hurricane that devastated Puerto Rico in 2017, as President Trump and his critics continue to feud over whether the administration exacerbated the human suffering from one of the worst natural disasters in recent memory.

House Oversight Committee Chairman Elijah E. Cummings (D-Md.) sent letters to the White House, the Department of Health and Human Services and the Federal Emergency Management Agency with an extensive request for records related to the federal response to Hurricane Maria, which killed thousands of people and caused billions of dollars in damage.

Cummings and several of his Democratic colleagues wrote acting White House chief of staff Mick Mulvaney for communications related to Puerto Rico before and after Hurricane Maria hit, noting that House Republicans have “refused to join Democrats in sending even one request” for White House records.

“For the past two years, the White House has refused to produce to the committee any documents regarding the Trump administration’s abominable response,” Cummings’s letter states. “The Oversight Committee is reestablishing its investigation of the Trump administration’s response to the hurricanes in Puerto Rico and the U.S. Virgin Islands — and the White House will not be exempt.”

Trump said Monday on Twitter that Puerto Rico had received $91 billion in federal aid already — a number debunked by fact-checkers — as Democratic critics and some experts have accused the administration of responding more slowly to Maria than it did to hurricanes in Florida and Texas.

“The Trump administration is committed to the complete recovery of Puerto Rico. The island has received unprecedented support and is on pace to receive tens of billions of dollars from taxpayers,” White House spokesman Judd Deere said in an email responding to earlier criticisms of the administration’s response to Puerto Rico.

Many of the documents related to FEMA’s response to the disaster were already requested in October 2017 by Cummings and then-Rep. Trey Gowdy (R-S.C.), who was the committee chairman at the time, but have not been turned over. A spokeswoman for FEMA said Monday that the agency had received the request and was working with the committee.

“FEMA failed to produce key documents responsive to that request despite multiple, repeated inquiries by committee staff,” Cummings’s letter states. “We are now writing to insist that you fully comply with this bipartisan request that was made more than 18 months ago.”

Cummings’s letter gives FEMA until May 20 to turn over the records, noting that if the agency fails to do so, House Democrats “will consider alternative means to obtain compliance.”

The request also asks for all documents related to a Sept. 29, 2017, email exchange with the Defense Department “reporting the discovery of mass graves in Puerto Rico.”

A spokesman for the White House did not immediately respond to a request for comment.