A Democrat on the Senate intelligence committee has said US President George W Bush's nominee for CIA director is too close to the White House.
Goss (left) is expected to be approved next week
Senator Jay Rockefeller told a hearing on Congressman Porter Goss' nomination he lacked the independence to restore credibility to intelligence agencies.
The CIA and other agencies were strongly criticised over the 11 September 2001 attacks.
Mr Goss told the committee he would work tirelessly to protect the US.
The BBC's Dan Griffiths in Washington says the Democrats are unlikely to press Mr Goss too hard for fear of being criticised for holding up national security reform, and he could be approved in the position as early as next week.
He will succeed former CIA director George Tenet, who resigned in July just before the release of the 9/11 Commission report that found what it called deep institutional failings in the US intelligence agencies.
Senator Rockefeller said he feared Congressman Goss, a Florida Republican, might use intelligence issues as a "political broadsword" against Democrats.
"Having reviewed your record closely, I have a number of concerns about whether your past partisan actions and statements will allow you to be the type of non-partisan, independent and objective national intelligence adviser our country needs," he said.
Mr Goss tried to reassure senators that he would be non-partisan.
"I understand completely the difference in obligations the position carries with it and that which the role of a congressman carries," he said.
The 65-year-old congressman, who is a former CIA agent, said his priorities for the role included improving human intelligence and analysis capabilities and liaising more closely with state and local law-enforcement agencies.
In July, the 9/11 Commission blamed US leaders for failing to comprehend the gravity of the threat posed by al-Qaeda and failing to avert the 2001 attacks.
Chairman Thomas Kean spoke of a failure of "policy, management, capability and, above all, imagination".
The commission recommended a wide-ranging overhaul of US intelligence services and congressional oversight.
About 3,000 people died when the hijacked airliners were crashed in New York, Washington and Pennsylvania on 11 September 2001.