The directive was issued on November 18 but was revealed by the White House only yesterday after a leak in The New York Times.
The current strength of CIA spies in the Directorate of Operations is believed to be around 4,500. The actual number is classified.
The US Defence Department is also studying and experimenting with new ways to use military forces to collect intelligence and conduct other covert operations.
In this realm -- technically called "intelligence preparation of the battlefield," some skeptics view the department as inching into covert actions, The Washington Post
The 50 per cent increase ordered by Bush in the CIA's clandestine operations calls for a new training facility and "even more aggressive recruiting, or lowering the quality of people," a former CIA official involved in the recruiting effort said, adding the increase called for is "huge."
Bush gives more powers to CIA chief
Of the current estimated strength of 4,500 in the Directorate of Operations, about a third are in the field as case officers who recruit agents, a former official said. The rest provide support from headquarters and overseas.
Overall, the CIA is believed to employ about 20,000 persons.
Bush has ordered the increases "as soon as possible" but one former senior agency official told the Post that the task could take "years" to accomplish.