Homeland Security Committee Democrats: Hearing cancellation 'inexcusable,' Republicans ‘fear’ San Juan mayor "What are they afraid of?" Cruz said of Homeland Security Committee Republicans.

 -- House Democrats unleashed a series of angry tweets Tuesday criticizing their colleagues across the aisle for postponing a Homeland Security Committee hearing to address hurricane recovery.

The Wednesday hearing was supposed to be Federal Emergency Management Agency Director Brock Long's first appearance in front of the House of Representatives panel. Now, attention has been turned to the partisan disagreement over the Democrats' request to add the mayor of San Juan, Puerto Rico to the witness list.

According to a Republican committee aide, Democrats requested Carmen Yulín Cruz's testimony on Friday afternoon, leaving what the aide said was too little time to plan a completed list of witnesses for the Wednesday hearing.

The hearing has been postponed and no new date has been set.

Cruz responded via a video posted to Twitter, accusing FEMA of a "deplorable" response to the devastation suffered by the U.S. territory.

"What are they afraid of?" Cruz said of the Homeland Security Committee's Republican members.

The mayor said she would spend her time in Washington D.C. meeting with people "who can handle the truth."

Cruz has been critical of the federal government's response in Puerto Rico and of the Trump administration in particular. The president previously slammed her for "poor leadership."

Cruz told ABC News' George Stephanopoulos on "This Week" that the focus should be on "saving lives" and not the U.S. territory's high rate of debt or what it may cost to rebuild.

On Tuesday, Long met with members of the Senate during a hearing that included largely positive reviews of FEMA's response, the agency's director and Governor of Puerto Rico, Ricardo Rossello.

One major topic discussed in the Senate hearing was a controversial power restoration contract with Whitefish Energy.

FEMA "would never have agreed to the language in that contract," Long said during the hearing today. He added that not a single federal dollar has gone towards reimbursing Puerto Rico for that contract.

The contract between Whitefish and Puerto Rico Electric Power Authority (PREPA) stated that "PREPA hereby represents and warrants that FEMA has reviewed and approved of this contract, and confirms that this contract is an acceptable form to qualify for funding from FEMA."

The Puerto Rico Electric Power Authority later released a statement saying that "any language in any contract between PREPA and Whitefish that states FEMA approved that contract is inaccurate."

When asked if there is cause for alarm in the awarding of that contract, the witnesses, including Long, remained silent or gently nodded their heads. There was a brief chuckle in the room, seemingly at the silence, and members moved on to the next question.

The Puerto Rico Electric Power Authority has asked New York State for assistance in restoring the island's power. That request is still being processed but is expected to go through.

Long told members of the committee today that he'd "never seen a more disturbing disaster in my life."

FEMA is spending $200 million a day on recovery efforts for four major disasters -- Hurricanes Maria, Irma and Harvey, and the California wildfires, according to Long.

ABC News' Erin Dooley contributed to this report.