Federal officials held a classified background briefing Thursday on the secret plutonium transfer to Nevada — a closed-door meeting with the state’s congressional delegation that left lawmakers frustrated over the lack of answers.

“The Department of Energy has lied to Nevadans and their elected representatives for decades, and I have no reason to believe that will change,” said Rep. Dina Titus, D-Nev.

Gov. Steve Sisolak, the state attorney general and the congressional delegation were taken by surprise last month when the DOE and the National Nuclear Security Administration disclosed in a court filing that one-half metric ton of weapons grade plutonium was shipped into the state while it was seeking an injunction to stop the transfer.

The state filed its motion in federal court on Nov. 30, 2018. A federal court hearing was held in January in Reno, where the government requested the injunction be denied to allow the transfer of the plutonium from South Carolina to take place.

The NNSA counsel, Bruce Diamond, later disclosed the transfer had taken place in a court filing Jan. 30, after the information was declassified. No information was made public about how the toxic material was shipped to the state, or which roadways were used.

Transfer of the plutonium from South Carolina to Nevada was completed before the state filed its motion in federal court, the federal government later claimed.

Titus said she “learned nothing new” in the one-hour meeting with Diamond and other NNSA and Energy officials about their “unchecked and unethical decision to secretly ship plutonium to Nevada.

“Instead of answering my questions directly, the Trump administration officials repeated meaningless platitudes,” she said in a statement issued after the morning meeting.

Sen. Catherine Cortez Masto, D-Nev., emerged from the meeting resolute to work closely with state officials and to use legislative tools in the Senate to get answers to questions that remain, an aide said.

Also attending the meeting was NNSA Administrator Lisa Gordon-Hagerty.

A request for comment from the NNSA was not immediately returned.

But federal officials have previously noted that DOE was under a federal court order in South Carolina to move one metric ton of plutonium from the Savannah River Site before January 2020.

A report issued last August said the plutonium would go to NNSA’s Nevada Test Site, north of Las Vegas, and the Pantex Plant near Amarillo, Texas.

The plutonium is to be eventually transferred to DOE laboratories at Los Alamos, New Mexico, but a timeline on that move has not been disclosed, prompting further concern among Nevada officials of when the shipment will leave the state.

Although information about the plutonium remains classified, DOE and NNSA have publicly said the shipment to Nevada was necessary.

The Department of Energy has lied to Nevadans and their elected representatives for decades, and I have no reason to believe that will change. In today’s meeting about @NNSANews's unchecked and unethical decision to secretly ship plutonium to Nevada, I learned nothing new. (1/2)

— Dina Titus (@repdinatitus) February 14, 2019