US President George W Bush has nominated Air Force General Michael Hayden as the new head of the CIA.
Gen Hayden is currently deputy director of national intelligence
Mr Bush described Gen Hayden, the former head of the National Security Agency (NSA), as "the right man to lead the CIA at a critical moment".
Lawmakers have expressed concern at putting a military man in charge of a civilian agency, and civil rights groups are also raising objections.
Porter Goss unexpectedly resigned as head of the CIA on Friday.
His successor must face Senate confirmation hearings.
The American Civil Liberties Union has urged the Senate to question Gen Hayden vigorously about the NSA's programme of domestic surveillance without warrants when he was in charge.
"Hayden's approval of warrantless surveillance on Americans raises serious questions about whether the CIA would be further unleashed on the American public," ACLU Executive Director Anthony Romero said in a statement.
He called on the Senate to use the Hayden confirmation hearing to investigate other allegations against the US intelligence community, including the reported use of secret prisons and extraordinary rendition of terror suspects.
Some members of Congress - including some Republicans - have baulked at the prospect of a general leading the CIA, saying it could give the Pentagon too much influence in intelligence gathering.
The BBC's Justin Webb says it is a measure of how enfeebled the Bush administration has become that even before the formal announcement, the decision on a new CIA director was already the subject of heated debate.
The president praised Gen Hayden, pointing to a long career in the US military and intelligence community, including time spent working as deputy to the current director of national intelligence, John Negroponte.
"Mike knows our intelligence community from the ground up. He has been both a provider and a consumer of intelligence," Mr Bush said.
"He has demonstrated an ability to adapt our intelligence services to the new challenges of the war on terror."
Mr Negroponte also commended Gen Hayden, calling him "a very, very independent-minded person".
He said Gen Hayden was well qualified for the position.
Accepting the nomination, Gen Hayden struck a positive note.
"In the confirmation process I look forward to meeting with leaders of the Congress, better understanding their concerns and working with them to move the American intelligence community forward," he said.
"This is simply too important not to get absolutely right."
Earlier, National Security Adviser Stephen Hadley appeared on US breakfast television shows to defend Gen Hayden's expected nomination.
"The question is not military versus civilian. The question is the best person to do the job," he told CBS.
The choice of Gen Hayden - who oversaw the controversial warrantless eavesdropping programme after 9/11 - has drawn some strong criticism among legislators.
"I do believe [Gen Hayden] is the wrong person, in the wrong place, at the wrong time," senior Republican Peter Hoekstra said.
Porter Goss's resignation surprised friends and pundits alike
Mr Hoekstra, chairman of the House Intelligence Committee, said there were already "ongoing tensions" between the CIA and the Pentagon.
His views were echoed by Democrat Senator Joe Biden who said the appointment could leave agents with the impression the CIA has been "just gobbled up by the defence department".
Porter Goss's resignation after less than two years as director, in which he was given the job of reforming the agency after a series of intelligence failures, came as a surprise.
He declined to comment on his departure, telling CNN that "it's one of those mysteries".
The White House denied as "categorically untrue" US media reports that the president had lost confidence in Mr Goss.