"We can dramatically lower the numbers [of attacks] ... but we can't prevent it," Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey said during a Wednesday speech at the National Press Club.
Most recently, Afghan forces killed an American soldier, a NATO contractor and two Afghan soldiers during an insider attack late last month.
While the attacks on American forces in Afghanistan will continue until the 2014 pullout deadline set by the White House, the four-star general was adamant the attacks would not throw the U.S. withdrawal strategy off track.
Currently, top U.S. defense officials are negotiating details of the future American military presence in Afghanistan after 2014, according to Dempsey.
The pending deal, expected to be finalized in early 2013, will "define our enduring presence" in a postwar Afghanistan according to Dempsey.
The recent uptick in insider attacks by Afghan forces against American troops "is not jeopardizing our objectives" in completing a U.S. pullout from the country within the next two years, he added.
Roughly 32,000 American troops have already been pulled from Afghanistan. Those troops were part of the White House's surge forces sent into the country in 2009.
The remaining 68,000 U.S. soldiers are scheduled to leave the country by 2014.
On Wednesday, Defense Secretary Leon Panetta outlined ongoing efforts insider the Pentagon to help stem the tide of insider attacks on coalition forces.
Panetta, along with Gen. John Allen -- the top U.S. commander in Afghanistan -- briefed top NATO defense leaders at the alliance's headquarters in Brussels.
"Insider attacks are a tragic part of every war. In this war, they are occurring with greater frequency than in the past," Panetta said during a Wednesday speech at NATO headquarters.
"We can only deny the enemy its objective by countering these attacks with all of our strength -- and fortifying our resolve with the signs of our progress," he added.
The steps taken by Allen and other coalition leaders in Afghanistan include enhanced training of U.S. and NATO troops to recognize the insider threat, coupled with an aggressive counterintelligence campaign to root out potential attackers, Panetta said.
Those efforts have been paired with a more thorough vetting process of recruits into the ANSF, to identify potential Taliban sympathizers or actual Taliban double agents looking to infiltrate Afghan forces, he added.
"What tests this alliance ... is not the problem of insider attacks. What tests us is how we respond to them," according to Panetta.
For their part, Afghanistan's military and intelligence leaders have also begun planting dozens of intelligence officers within the military and national police forces across the country.
Afghan intelligence agents have even gone so far as to ban on all cellphones by new ANSF recruits as a way to limit potential communication between those recruits and Taliban commanders.
That joint effort, according to Dempsey, shows that Kabul is taking the threat of insider attacks just as seriously as defense and intelligence officials in Washington.
"Everyone understands it," he said Wednesday, regarding the morale-crushing impact of insider attacks on coalition and Afghan forces.
But that joint U.S., NATO and Afghan response, particularly in attempting to pinpoint Taliban members inside the ANSF, has been lackluster at best.
In September, Dempsey admitted U.S. forces were no closer to determining how deep the Taliban's reach into the ANSF has gotten.
"As for what percentage of the insider threat is related to infiltration or radicalization, I mean, it's really difficult to determine," Dempsey told reporters during a Sept. 28 press conference at the Pentagon.
"I'm sure a certain percentage of it is. And we're treating it … as a threat," he told reporters at the time.
In March, Allen characterized the insider attacks against coalition troops as a fact of life on the ground in the country.
Panetta agreed with Allen's assessment during the same DOD press briefing in September.
"I expect that there will be more of these high-profile attacks," Panetta said at the time. "The enemy will do whatever they can to try and break our will using this kind of tactic. That will not happen."