WASHINGTON, D.C. — It remains uncertain whether the Afghan security forces will be able to carry out essential functions by the time the U.S. draws down to a small military presence at the end of 2016, according to the Special Inspector General for Afghanistan Reconstruction (SIGAR).

This is due to questionable assessments that fail to paint a clear picture of Afghan National Defense and Security Forces (ANDSF) capability.

The Ministries of Defense and Interior that manage the ANDSF, which includes police and military units, will not be able to fulfill its responsibilities by the time the U.S. withdraws nearly all its forces, added SIGAR, a watchdog agency appointed by Congress.

Nevertheless, Secretary of Defense Ashton Carter recently told lawmakers that he sees “great promise in Afghanistan that we’re going to achieve the objective we set ourselves,” asserting that “we can see the kind of success we’ve striven for so long ahead in Afghanistan.”

Since the Afghanistan war started on October 7, 2001, Congress has appropriated an estimated $110 billion for Afghan reconstruction, including $62.5 billion to develop Afghanistan’s security institutions. Billions more in U.S. taxpayer funds are expected to be appropriated in the foreseeable future.

Despite all the money spent, SIGAR’s chief, John Sopko, identified the capacity and capabilities of the ANDSF as being at risk last December.

Sopko expressed concern about the capability of the Afghan security forces, the accuracy of its manpower, and its long-term sustainability when he spoke at the Center for Strategic and International Studies (CSIS) on Wednesday.

“After 10 years of reporting, including times when ANDSF units have been rated as [operating] independent [of U.S. troops], it is troubling that the MAAR [Monthly ANDSF Assessment Report] found that the Afghan Army had not achieved the highest rating level in any category,” Sopko told the CSIS audience.

The capability and force strength of ANDSF appear to be an enigma.

MAAR is only the latest metric used to asses the Afghan forces capabilities. Since 2005, the tool used to gauge the ANDSF has changed four times.

SIGAR has long questioned the methodology used to asses the Afghan security forces’ capabilities.

“It remains to be seen, since we’ve just seen it, if the MAAR will be a useful tool for determining Afghan security force capability, but after 10 years of assessments where ANDSF ratings have yo-yoed with every new system, I cannot help but be a little skeptical,” Sopko declared at CSIS.

The Ministries of Interior and Defense that manage the national police and army, respectively, are also falling short of meeting expectations.

“It’s not just the Afghan troops we at SIGAR are worried about. It is the Afghan ministries themselves,” said Sopko. “Senior U.S. [military] leaders in Afghanistan have told me that it will take years for the Afghans to master their essential functions, as we define them, and that they will not master any of them by the time the U.S. shrinks its military presence at the end of 2016. That is significant.”

“The most recent assessments of the Ministries of Defense and Interior seem to confirm what the [U.S.] generals told us,” he continued. “In October 2014, only four offices in those ministries were deemed ‘capable of autonomous operations.’”

The Pentagon chief sounded a more positive tone when commenting on President Obama’s Afghanistan strategy while testifying before a congressional panel.

“I think that our strategy has paid off in Afghanistan,” he affirmed, later adding, “I don’t want to be to rosy about anything, but I think that we can see the kind of success we’ve striven for so long ahead in Afghanistan.”

“Everybody wants success here, and to have gotten so close, so to speak, to get to the five yard line and fumble the ball, nobody wants to do that,” also said Carter. “Nobody is going to do that.”

During his speech at CSIS, SIGAR’s head reiterated that the Pentagon does not know the exact number of personnel currently serving in the Afghan security forces or how many of them are getting paid.

Such data enables military leaders to determine operational capabilities.

“The U.S. military says it will make large gains in the coming 19 months” in trying to rectify all the ongoing problems afflicting the ANDSF, Sopko said.

“Try as I may, I must confess again to some skepticism and concerns,” he continued. “Why would one expect to see faster progress now rather than at any point during the 13-year reconstruction effort when the number of U.S. and Coalition personnel available to train, advise, and assist it’s greatly reduced?”

Follow Edwin Mora on Twitter: @EdwinMora83