By Daniella Diaz and Phil Mattingly, CNN

(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.

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 President Donald 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."

The statement 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!" Trump tweeted.

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

Trump "thought it was the right time for the transition with the upcoming North Korea talks and various trade negotiations," a senior administration official said. "POTUS asked Tillerson to step aside on Friday."

Tillerson did not speak to Trump and is unaware of the reason behind his firing, Undersecretary for Public Diplomacy Steve Goldstein said.

This story is breaking and will be updated.