The Trump administration has abruptly canceled three classified congressional briefings related to the ongoing Iran crisis, in some cases providing little or no explanation for doing so.

The State Department canceled two briefings that were scheduled for Wednesday, Senate and House aides confirm to CNN. The Pentagon has also canceled Thursday’s classified briefing on Iran for the House Armed Services Committee due to scheduling issues, according to a US defense official and house aide.

John Rood, the Defense Department’s top policy official, had been expected to deliver that briefing. A spokesperson for the Pentagon said that the Department of Defense was working to schedule a time to conduct the briefing.

Congressional lawmakers were slated to receive a briefing on embassy security while the Senate Foreign Relations Committee expected to be briefed on the administration’s Iran policy and authorities for the use of force before the last-minute schedule changes.

Wednesday’s House side briefing was originally going to focus on situation in the African country of Burundi but the topic was changed to a global assessment of embassy security at the request of congressional staff after the strike that killed Iranian General Qasem Soleimani.

An aide tells CNN the request of topic change was made January 7. The law requires monthly briefings for national security committees in both chambers on threats to embassies.

“This has not been rescheduled. We don’t know why it was canceled,” the aide said. “Staff is pissed.”

The staffer told CNN there was no noticeable chill in the planning process for the briefing on embassy security after the State Department shifted the topic.

“They understood that this was a reasonable request,” the staffer said.

Politico was first to report the embassy security briefing cancellation.

CNN reported on Monday that State Department officials involved in US embassy security were not made aware of imminent threats to four specific US embassies, two State Department officials tell CNN, further undermining President Donald Trump’s claims that the top Iranian general he ordered killed earlier this month posed an imminent threat to the diplomatic outposts.

Without knowledge of any alleged threats, the State Department didn’t issue warnings about specific dangers to any US embassy before the administration targeted Soleimani, Iran’s second most powerful official, according to the sources.

The State Department sent a global warning to all US embassies before the strike occurred, a senior State Department official said and the department spokesperson confirmed, but it was not directed at specific embassies and did not warn of an imminent attack.

Wednesday’s cancellation also comes as former US Ambassador to Ukraine Marie Yovanovitch on Tuesday called for an investigation into the “disturbing” notion that she was under surveillance from associates of the President’s personal lawyer, Rudy Giuliani, following the release of documents that suggested she was being monitored.

On the Senate side, the State Department also postponed Wednesday’s classified hearing on Iran at the last moment as criticism continues to mount from Capitol Hill on the Trump administration’s legal rationale for its strike against Iran’s top military commander earlier this month.

“State 100% canceled the briefing. We know they will vaguely claim it was a logistical issue, even though this briefing had been already locked into the schedule for days,” the aide said.

A Republican aide however downplayed it as “just a scheduling change.”

“The briefers had a conflict and State has assured us that we will reschedule to have several hearings on Iran in the coming weeks,” the aide said.

Brian Hook, the State Department’s Special Representative for Iran, and David Schenker, Assistant Secretary of State for Near Eastern Affairs were expected to brief the Senate Foreign Relations Committee. Schenker returned from a trip to the Middle East last week that included a stop in Iraq.

Marik String, an official in the State Department’s Office of Legal Advisor was also expected to brief the committee.

The State Department did not respond to CNN’s request for comment regarding either schedule change.