Washington (CNN) Senior congressional Democrats were not notified before the US strikes that killed Iran Quds Force commander Qasem Soleimani, something critics say is a breach of protocol over how the top leadership is typically briefed over sensitive military actions that carry great risks to the United States.

The four Democrats in the "Gang of Eight," a group of top congressional leaders who are generally privy to sensitive information that the rest of Congress is not always briefed on, include House Speaker Nancy Pelosi, who Thursday night criticized the administration for not consulting with Congress ahead of the attack.

It's unclear if any of the four Republican leaders were briefed ahead of time, but House Minority Leader Kevin McCarthy spent Thursday with President Donald Trump at his Florida resort. Senate Judiciary Committee Chairman Lindsey Graham, who is not a member of the Gang of Eight but who is a close ally of Trump's, said on Fox News Friday morning that he was briefed about the potential operation when he was with Trump in Florida this week.

After the attack at the Baghdad airport, Pelosi spoke to Defense Secretary Mark Esper, a Democratic source told CNN. The two talked for about 13 minutes around 9:40 p.m. eastern time Thursday, hours after the attack.

The move is the latest indication that Trump typically keeps his close GOP confidantes in the loop over national security matters that have traditionally been handled more on a bipartisan basis, infuriating Democrats who say such highly sensitive matters should be devoid of partisanship.

The Gang of Eight is made up of the top Democrats and Republican leaders in the House and Senate as well as the chairs and ranking members of the House and Senate intelligence committees. It is customary for this small group of lawmakers to be briefed on such actions, but the group does not always get advanced notice of a military operation.

Senate Minority Leader Chuck Schumer and Sen. Mark Warner, the top Democrat on the Senate Intelligence Committee, were not briefed ahead of the Soleimani attack. A spokesman for House Intelligence Chairman Adam Schiff declined to comment.

The lack of briefings come as Trump has engaged in a bitter and personal fight with Democratic leaders, lashing out time and again at Pelosi and Schiff as they pushed to impeach him over allegations he abused his office over his conduct with Ukraine and obstructed the impeachment inquiry.

He has ridiculed Pelosi, Schiff and Schumer, often taunting them with schoolyard insults and accusing them of betraying the country. Moreover, Pelosi and Trump have had multiple raucous face-to-face meetings, including some that have ended abruptly amid the President's furious attacks against his Democratic adversaries.

It's unclear whether McCarthy got advanced notice of the attack while in Florida with Trump, or whether the other GOP members in the Gang of Eight -- Senate Intelligence Chairman Richard Burr and House Intelligence Committee ranking member Devin Nunes -- were told ahead of time. A spokesman for Senate Majority Leader Mitch McConnell declined to comment.

Speaking on the Senate floor, McConnell said the operation "may prove controversial or divisive" in this political environment. He said he anticipated and welcomed a debate about America's interests and foreign policy in the Middle East, but recommended that senators "wait to review the facts and hear from the administration before passing much public judgment on this operation and its potential consequences."

McConnell said the Trump administration will brief staff Friday on the situation in Iraq and that he is working to arrange a classified briefing for all senators early next week.

Schumer, speaking after McConnell, said he feared that serious questions regarding the operation's legal basis and Iran's potential response may not have been fully considered.

"The President does not have the authority for a war with Iran," Schumer said, and would need congressional approval for an increase in troops and "and potential hostility over a longer time."

Schumer added: "This action may well have brought our nation closer to another endless war -- exactly the kind of endless war the President promised he would not drag us into."

Warner, who a source says spoke with CIA Director Gina Haspel on Friday, was critical of the lack of Gang of Eight briefing.

"The concern I have is America should have the ability to have the time and place to take action. My concern is if we look at the region, did the administration think through the full ramifications of this attack," Warner said in an interview with CNN.

"Clearly the Iranians will respond," he added. "Whether this was the appropriate time and place to take action on that threat is I think I and others are going to need to be briefed on."

The latest developments are similar to the end of October when the US military killed ISIS leader Abu Bakr al-Baghdadi. Top Democrats, including Pelosi, were left in the dark about the raid. Trump contended he did not tell Pelosi about the raid because he didn't want news of the operation to leak.

In that October attack, McConnell also was not briefed, but he told CNN at the time he was okay with that.

"I wasn't [briefed], but I was in the similar position when President Obama ordered the attack on Osama bin Laden. I was not called in advance then, nor do I expect to be called in advance now," McConnell said in October. "The administration attempted to let me know. I didn't connect with them before the President's press conference, but they attempted to let me know before he went public. So the two situations were handled exactly the same from my point of view."

While McConnell didn't get notified ahead of the Baghdadi attack, a small group of congressional Republicans -- including members who are not on the relevant committees overseeing military operations -- were invited to the White House ahead just days ahead of the raid and were told an announcement was coming, according to a source familiar with the matter.

This story has been updated to add Warner's comments.