WASHINGTON, March 13: US State Department spokesman Philip J. Crowley lost his job on Sunday after criticising the Pentagon last week for detaining an American soldier accused of feeding documents to Wikileaks.

Deputy Assistant Secretary Michael Hammer, who moved to the State Department a few weeks ago from the National Security Council, will serve as acting spokesman.

Mr Hammer may also be nominated to replace Mr Crowley, a position that needs Senate confirmation.

“It is with regret that I have accepted the resignation of Philip J. Crowley as assistant secretary of state for public affairs,” said Secretary of State Hillary Clinton in a statement.

CNN reported that Mr Crowley had “abruptly resigned” under “pressure from White House officials because of controversial comments he made last week about the Manning case”.

On Friday, Mr Crowley denounced the conditions of Private Bradley Manning, who allegedly leaked hundreds of thousands of secret documents to Wikileaks, as “ridiculous, counterproductive and stupid”.

His remarks forced President Barack Obama to address those comments in a news conference and defend Mr Manning's confinement.

Mr Manning's lawyers say their client is subjected to 23-hour-a-day solitary confinement. Military officials prevent him from exercising in his cell. They also have punitively imposed “suicide watch” restrictions on him against the recommendations of psychiatrists. Mr Manning is also subjected to prolonged, forced nudity.

Mr Crowley also issued a statement on Sunday, acknowledging that his remarks about Private Manning led to his departure from the State Department. “Given the impact of my remarks, for which I take full responsibility, I have submitted my resignation,” he said.

Mr Crowley noted that the soldier had committed “a serious crime” by disclosing classified information without authorisation.

But his comments about “the conditions of Mr Manning's pre-trial detention were intended to highlight the broader, even strategic impact of discreet actions undertaken by national security agencies every day and their impact on our global standing and leadership,” he wrote.

“The exercise of power in today's challenging times and relentless media environment must be prudent and consistent with our laws and values,” Mr Crowley said.