James Clapper, Director National Intelligence fumbled in conveying the administration's message about Libya dictator's fate and the administration distanced itself from the remarks.
But publicly, a White House spokesperson Jay Carney said Clapper enjoyed the full confidence of the president.
President Barack Obama as well as his Secretary of State Hillary Clinton have in public comments stated that they see the days of Gaddafi in power as numbered.
It was the latest of a series of public gaffes by Clapper, who earlier had raised eyebrows by describing the banned Muslim Brotherhood in Egypt as a "secular force".
Deposing before the Congressional Armed Forces Committee, Clapper said that Gaddafi's military might was stronger than had been described.
The intelligence chief he foresaw that Gaddafi will not step down to offer any speedy resolution of the Libyan crisis.
His remarks that Gaddafi would prevail raise the hackles of lawmakers and a Senator Lindsuy Graham quickly urged Clapper to resign.
"Unfortunately, this isn't the first questionable comment from the DNI Director," Graham said adding "However it should be the final straw."Another faux pas by Clapper came in December when he said on national television that he was in the dark about a terror plot inspired by al-Qaeda to hit targets in US and Europe.
That time too, he was defended by the Obama administration.In his congressional testimony, Clapper said Libyan air defences, including radar and surface-to-air missiles (SAM), were "quite substantial" in comments likely to intensify the debate over a no-fly zone.
The US intelligence chief also disclosed that Gaddafi's army and fighters possessed portable SAMs that could pose problems to imposing a no-fly zone.
He also said that Libya had 80 aircraft including Russia supplied advanced Sukhoi and MIG fighters though their fighter pilots could not shoot straight.