Gen. David Petraeus, the head of US Central Command, signed an order in September authorizing Special Operations forces to deploy to both allied and hostile nations in the Mideast, Central Asia and the Horn of Africa to conduct surveillance missions and partner with local forces, two officials said on condition of anonymity because it involves clandestine forces.

The seven-page order also appears to authorize specific operations in Iran, most likely to gather intelligence about the country's nuclear program or identify dissident groups that might be useful for a future military offensive, according to The New York Times, which first disclosed the directive in Tuesday’s editions. Also citing anonymous sources, the newspaper said that the new order does not authorize offensive action, but rather its goal is to build new networks to “penetrate, disrupt, defeat or destroy” militant groups, including Al-Qaeda, and “prepare the environment” for future attacks.

As such, the Joint Unconventional Warfare Task Force Execute Order of Sept. 30 to a large extent is aimed at codifying established activities — some of which have been under way for years — and more systematically align them and fund them under Central Command's special operations component, one defense official said.

One such major escalation in the region is the work already under way with Yemen, the country where Al-Qaeda linked militants planned the failed Christmas Day airliner attack over Detroit by the so-called underwear bomber. In that case, the Defense Department plans to more than double to $150 million this year the money spent on helicopters, weapons and other counterterrorism efforts to help local security forces go after the group Al-Qaeda in the Arabian Peninsula.

Aside from that expansion, it was unclear Tuesday precisely what other operations or missions in recent months might have stemmed from the new order.

Officials said that many top commanders, Gen. Petraeus among them, have advocated an expansive interpretation of the military’s role around the world, arguing that troops need to operate beyond Iraq and Afghanistan to better fight militant groups.

The order, which an official said was drafted in close coordination with Adm. Eric T. Olson, the officer in charge of the United States Special Operations Command, calls for clandestine activities that “cannot or will not be accomplished” by conventional military operations or “interagency activities,” a reference to American spy agencies.

While the CIA and the Pentagon have often been at odds over expansion of clandestine military activity, most recently over intelligence gathering by Pentagon contractors in Pakistan and Afghanistan, there does not appear to have been a significant dispute over the September order.

A spokesman for the CIA declined to confirm the existence of Gen. Petraeus’ order, but said that the spy agency and the Pentagon had a “close relationship” and generally coordinate operations in the field.

During the Bush administration, Defense Secretary Donald H. Rumsfeld endorsed clandestine military operations, arguing that Special Operations troops could be as effective as traditional spies, if not more so.

Unlike covert actions undertaken by the CIA, such clandestine activity does not require the president’s approval or regular reports to Congress, although Pentagon officials have said that any significant ventures are cleared through the National Security Council. Special Operations troops have already been sent into a number of countries to carry out reconnaissance missions, including operations to gather intelligence about airstrips and bridges.