The Pentagon is planning to ramp up its spying operations against high-priority targets such as Iran under an intelligence reorganization aimed at expanding on the military’s espionage efforts beyond war zones, a senior defense official said Monday.

The newly created Defense Clandestine Service would work closely with the CIA — pairing two organizations that have often seen each other as rivals — in an effort to bolster espionage operations overseas at a time when the missions of the agency and the military increasingly converge.

The plan, the official said, was developed in response to a classified study completed last year by the director of national intelligence that concluded that the military’s espionage efforts needed to be more focused on major targets beyond the tactical considerations of Iraq and Afghanistan.

The new service will seek to “make sure officers are in the right locations to pursue those requirements,” said the official, who spoke on the condition of anonymity to describe the “realignment” of the military’s classified human espionage efforts.

The official declined to provide details on where such shifts might occur, but the nation’s most pressing intelligence priorities in recent years have included counter­terrorism, nonproliferation and ascendant powers such as China.

Creation of the new service also coincides with the appointment of a number of senior officials at the Pentagon who have extensive backgrounds in intelligence and firm opinions on where the military’s spying programs — often seen as lackluster by CIA insiders — have gone wrong.

Defense Secretary Leon E. Panetta, who signed off on the newly created service last week, served as CIA director at a time when the agency relied extensively on military hardware, including armed drones, in its fight against al-Qaeda.

Michael Vickers, the undersecretary of defense for intelligence and the main force behind the changes, is best known as one of the architects of the CIA’s program to arm Islamist militants to oust the Soviets from Afghanistan in the 1980s. He is also a former member of U.S. Special Operations forces.

The realignment is expected to affect several hundred military operatives who already work in spying assignments abroad, mostly as case officers for the Defense Intelligence Agency (DIA), which serves as the Pentagon’s main source of human intelligence and analysis.

The official said the new service is expected to grow “from several hundred to several more hundred” operatives in the coming years. Despite the potentially provocative name for the new service, the official played down concerns that the Pentagon was seeking to usurp the role of the CIA or its National Clandestine Service.

This “does not involve new manpower . . . does not involve new authorities,” the official said. Instead, the official said, the DIA is shifting its emphasis “as we look to come out of war zones and anticipate the requirements over the next several years.”

Congressional officials said they were seeking more details about the plan.

“My question is, why? What’s missing and what’s going on?” said a senior Senate aide who had been given a preliminary briefing on the new service.

In some respects, the broad outlines of the plan are reminiscent of Pentagon efforts under Defense Secretary Donald H. Rumsfeld to move the military into areas of intelligence that had long been the domain of the CIA.

But a second congressional official, who also was not authorized to discuss the program publicly, said the coordination behind the new plan, in which the DIA’s program will be more closely modeled on its CIA counterpart, has eased some of those long-standing concerns.

“If this were an attempt of the type we saw during the Rumsfeld years to consolidate human intelligence to have a better bulwark against what the CIA is doing, that would be a concern,” the second congressional official said. “But I don’t think that’s what's going on.”

The plan was unveiled about a week after a senior U.S. Army officer with extensive experience in Special Operations and counter­insurgency fighting in Iraq and Afghanistan was nominated to serve as the next chief of the DIA.

While serving in Afghanistan, Lt. Gen. Michael T. Flynn published a harsh critique of intelligence operations in that country, criticizing collectors as being too focused on tactical threats and failing to understand the broader demographic and political context of the battlefield.

About 15 percent of the DIA’s case officers will be part of the Defense Clandestine Service, the defense official said. New, more clearly delineated career paths will give DIA case officers better opportunities to continue their espionage assignments abroad, he said.

The new service fits into a broader convergence trend. U.S. Special Operations forces are increasingly engaged in intelligence collection overseas and have collaborated with the CIA on missions including the raid on Osama bin Laden’s compound in Pakistan and ongoing drone strikes in Yemen.

The blurring is also evident in the organizations’ upper ranks. Panetta previously served as CIA director, and that post is currently held by retired four-star Army Gen. David H. Petraeus.