'We need to be prepared across the board for what a new president will bring,' Admiral Mike Mullen, the chairman of the Joint Chiefs of Staff, told a town hall-style meeting for military personnel and civilians who work at the Pentagon on Thursday.

'We need to be the solid foundation, totally apolitical in our view, totally supportive of the president of the United States, whoever he or she might be in the future,' he said.

Adm Mullen did not mention any candidates in his remarks. But he told reporters afterwards he was worried pulling out of Iraq quickly could reverse gains in security achieved since President George W. Bush sent in extra troops last year.

Both the remaining Democratic candidates for president, Senators Barack Obama and Hillary Clinton, have pledged to begin withdrawing forces from Iraq quickly after they take office next January if they win November's election.

'I do worry about a rapid withdrawal ... in a situation that wouldn't call for that in terms of the conditions on the ground,' Adm Mullen said in response to a question about planning for a change in administration.

He said such a withdrawal would 'basically turn around the gains that we have achieved and struggled to achieve'. He stressed, however, he regarded civilian control of the military as a 'bedrock' principle.

'When a new president comes in, I'll get my orders and we'll carry them out,' he said. -- REUTERS