Donald Trump promised during the campaign to implement a "secret plan" to defeat ISIS, including a pledge to "bomb the hell out of" the terror group in Iraq and Syria.

Now, the Pentagon has given him a secret plan, but it turns out to be a little more than an "intensification" of the same slow and steady approach that Trump derided under the Obama administration, two senior officials who have reviewed the document told NBC News.

The plan calls for continued bombing; beefing up support and assistance to local forces to retake its Iraqi stronghold Mosul and ultimately the ISIS capital of Raqqa in Syria; drying up ISIS’s sources of income; and stabilizing the areas retaken from ISIS, the officials say.

Two prominent military strategists told NBC News they fear the plan is insufficient, and won’t fulfill Trump’s pledges to "totally obliterate ISIS" and do it quickly.

"The current plan to defeat the Islamic State is just like that old saying: Plan B is just, ‘Try harder at Plan A,’" said retired Admiral James Stavridis, an NBC News analyst and dean of The Fletcher School of Law and Diplomacy at Tufts University. "We have not come up with new ways of approaching this. I would say the president might want to send that report back to his team to take another hard look."

"[W]e've been attacking their fingers and their toes."

Retired Air Force Gen. Dave Deptula, who planned the air campaign in the first Iraq war and is a vigorous advocate of conventional air power, insisted that the military should be directing more firepower at ISIS.

"If you view the Islamic state as a body, what's been going on with the current strategy is we've been attacking their fingers and their toes," said Deptula.

The bombing campaign against ISIS over the last two and half years, Deptula noted, has been commanded by Army generals. He says more air power is needed and that the Army should no longer be commanding the airstrikes against ISIS.

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"I you want to win a football game, would you put in a swimming team coach to lead the team during the Super Bowl?" he asked. "No."

Last week, the commander of U.S. Central Command, Gen. Joseph Votel, signaled to Congress that the current approach is working. "The Counter-ISIS campaign has entered its third year and we are on track with the military plan to defeat the terrorist organization in Iraq and Syria," said Votel in testimony prepared for the Senate Armed Services Committee.

Votel said that the coalition’s efforts had killed dozens of senior ISIS leaders, downgraded the terror group’s forces and capabilities and taken back "large swaths" of territory.

"While we continue to make great strides towards countering ISIS trans-regionally, we recognize that we are dealing with a highly adaptive enemy," said Votel. "We will defeat ISIS militarily; however, a lasting defeat of this enemy will not be achieved unless similar progress is made on the political front."

'They'll Be Gone Quickly'

The irony of the similarities between the Obama plan and the Trump plan is that as a candidate, Trump repeatedly called Obama’s ISIS strategy a failure

"We have to be unpredictable starting now. But they're going to be gone," he said in August. "ISIS will be gone if I'm elected president. And they'll be gone quickly."

Pentagon spokesman Navy Capt. Jeff Davis told NBC News that the defense department "delivered a preliminary plan to accelerate the defeat of ISIS" — a plan that is "is serving as the basis for broader discussions with the White House and our interagency partners."

Davis said the preliminary plan sent to the White House is a grand strategy - which places even more emphasis on diplomacy, economics and information than it does on the military. It creates, he says, a framework for more tactical questions to be answered later.

The plan "draws upon the whole-of-government, better synchronizing public diplomacy, cyber, information, financial, as well as military instruments of power, and it enhances our coordination across regions," he added.

The Pentagon’s ISIS plan highlights four "next plays," say officials who’ve seen it, suggesting "acceleration" in all of them. The "next plays" include "Support Iraqi Security Forces to capture Mosul" and "Support and develop more local forces in Syria." Both of those efforts have been underway for nearly a year.

According to a defense official, the plan eliminates much of the cumbersome decision-making process previously in place. This streamlining, the official said, will allow decisions to be made more rapidly and with greater flexibility.

Officially the U.S. government says it has 500 American troops deployed on the ground in Syria, and another 5,200 in Iraq. Senior military officials told NBC News the actual numbers are at least double that.

Stavridis said he thinks the U.S. needs "a minimum of 10,000 U.S. troops" on the ground to help local forces "cut out the heart of the Islamic State in Raqqa."

Nearly every expert agrees that military victory over ISIS is only the first step. Unless the U.S. and its partners deal with the conditions that created ISIS in the first place — grievances among Sunni Muslims who live in Iraq and Syria, where the governments are controlled by non-Sunnis — another version of ISIS is likely to rise up as soon as the conquering force departs.

And neither the Obama Administration nor the Trump Administration has been able to do much in getting the Shiite-dominated Iraqi government to grant political rights to Sunnis, experts say.

As for the Alawite-led Syrian government, it is bombing its Sunni opponents on a regular basis.