Washington (CNN) Several senior Republican aides in both chambers told CNN they were given no heads up on the President's decision to replace Rex Tillerson with Mike Pompeo as secretary of state, as well as the move to nominate Gina Haspel as CIA director.

House Speaker Paul Ryan received a phone call telling him this was coming, a source said, but aides said other Hill Republicans were given no heads up.

"(We found out from) Twitter. And news alerts, just like everyone else, apparently," one senior GOP aide who works on foreign policy said when he was asked how the Tillerson news reached the Hill.

Sen. John Cornyn, the Senate's number two Republican, said he was surprised by the news this morning of Tillerson's firing, adding he was not given a heads up by the White House and only found out by news alerts on his phone.

"Rex Tillerson is a great American and I'm sorry to see him go," he said. "I also hold Mike Pompeo in very high regard."

The comments came after news broke Tuesday morning that Trump fired Tillerson.

"Mike Pompeo, Director of the CIA, will become our new Secretary of State. He will do a fantastic job! Thank you to Rex Tillerson for his service! Gina Haspel will become the new director of the CIA, and the first woman so chosen. Congratulations to all!" President Donald Trump tweeted.

White House press secretary Sarah Sanders told reporters that Trump asked Tillerson to step aside.

Cornyn worries about confirmation process

Cornyn said he was concerned with having two confirmation hearings, one for Pompeo and another for Haspel, considering Congress' legislative schedule for the year.

"With everything else we have to do around here, having the prospect of two additional confirmation fights perhaps is going to be a challenge," he said.

On the immediate agenda are a banking bill, a bill to fight sex trafficking and a proposal to avert a government shutdown ahead of a deadline next week.

Cornyn continued: "It would help us get more things done if there weren't so many distractions. But that is why we do our job here and they do their job at the White House."

He also said he is confident that Pompeo, who was confirmed by the Senate for his position at the CIA , will be confirmed by the Senate.

Republican leaders, defense hawks praise Trump's nominees

In spite of being in the dark, several Republicans were quick to praise Pompeo, who is a former member of Congress, as well as Haspel. Sen. Tom Cotton was one of the first to praise Trump's decision in a statement Tuesday.

"Mike Pompeo is an outstanding selection as our next Secretary of State ... While it's a loss for the CIA, Gina Haspel is also an excellent choice to become the new CIA director," he said in a statement Tuesday. "I look forward to supporting them both during the confirmation process and working with them in the years to come."

South Carolina Republican Sen. Lindsey Graham, a defense hawk, also praised the Pompeo choice.

"I cannot think of a better choice for our new secretary of state than Mike Pompeo," Graham said in a statement, adding later, "No one has a stronger relationship with President Trump than Mike Pompeo. This relationship will empower him throughout his tenure as secretary of state."

Senate Majority Leader Mitch McConnell released a statement thanking Tillerson for his service, saying the US "national security was enhanced through his service."

"Rex took the depth of knowledge and experience formed of decades as one of America's leading business executives and adapted it to the world of diplomacy, quickly learning the details and national security imperatives he pursued as Secretary of State," he said in a statement.

And at least one Democrat had something positive to say about Haspel's nomination so far.

Florida Sen. Bill Nelson a former member of the Senate Intelligence Committee, acknowledged he didn't know Haspel, but praised her experience.

"I think the fact that she is a 30-year professional is a good sign," he said.

Sen. Dianne Feinstein, the Democrat on the Senate Judiciary Committee who had blocked Haspel's confirmation for a previous post in 2013, spoke warmly of Haspel, saying they've had long conversations about the Bush-era torture programs and calling her a good deputy CIA director.

She said she would wait until the confirmation hearings to determine how she'd vote on Haspel's nomination to become CIA director.

"I have spent some time with her. We have had dinner together. We have talked. Everything I know is that she has been a good deputy director of the CIA," Feinstein said. "I think hopefully the entire organization learned something from the so-called enhanced interrogation program.

"I think it's something that can't be forgotten," Feinstein added. "I certainly will never forget it. I won't let any director forget it."

Democrats say Trump's decision evidence of chaos

Most Democrats meanwhile pointed to the staffing changes as a sign of an administration in chaos.

Sen. Chris Coons, a Delaware Democrat on the Senate Foreign Relations Committee, told reporters he doesn't understand why Trump would dismiss Tillerson when he has been the one pushing for diplomacy with North Korea within the Trump administration.

"That he chose to dismiss his secretary of state in a manner more reminiscent of an episode of 'The Apprentice' than the respect he's due for his service — at the exact moment that diplomacy is essential to securing some path forward with North Korea — strikes me as just irresponsible," Coons said.

House Minority Leader Nancy Pelosi said "Tillerson's firing sets a profoundly disturbing precedent."

"It is no wonder that the President has trouble attracting high-caliber people to his administration when he undercuts and humiliates those he supposedly respects," the California Democrat said in a statement.

Democratic Sen. Tammy Duckworth issued a statement slamming Trump for firing Tillerson and choosing "chaos and turmoil."

"Rather than taking serious steps to ensure stability or fill our diplomatic corps, once again Donald Trump chose chaos and turmoil today over the kind of leadership the American people desperately need and deserve," she said in a statement. "Even worse, his new nominee to be secretary of state -- the highest diplomatic post in the nation -- has not expressed any moral opposition to torture."

Sen. Bob Menendez, the top Democrat on the Senate Foreign Relations Committee, told reporters that "there are different sets of skills" for State and the CIA.

He said "being the CIA director requires one set of skills, being secretary of state requires diplomatic skills."

When he asked if Pompeo had the necessary skills, he responded, "we'll have to wait and see."