Washington (CNN) Hours after it was announced that Andrew McCabe would be stepping down from his post at the FBI, former FBI Director James Comey responded to the surprising early departure of the agency's deputy director on Twitter.

"Special Agent Andrew McCabe stood tall over the last 8 months, when small people were trying to tear down an institution we all depend on. He served with distinction for two decades. I wish Andy well. I also wish continued strength for the rest of the FBI. America needs you," Comey tweeted from his verified account on Monday night.

Special Agent Andrew McCabe stood tall over the last 8 months, when small people were trying to tear down an institution we all depend on. He served with distinction for two decades. I wish Andy well. I also wish continued strength for the rest of the FBI. America needs you. — James Comey (@Comey) January 30, 2018

McCabe was a central target of President Donald Trump's ire toward the FBI over the investigation into potential collusion between his campaign and Russia during the 2016 election, as well as the bureau's handling of former Democratic rival Hillary Clinton's email case.

Trump learned about McCabe's departure Monday morning, a White House official told CNN. The President did not answer a reporter's question at the White House about the departure. White House press secretary Sarah Sanders said Trump had not been part of McCabe's choice to step down and that the White House had not been part of the decision.

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