The U.S. army reportedly deployed a specialized "psychological operations" team in 2009 to help convince American legislators to boost funding and troop numbers for the war in Afghanistan.
Lt. Gen. William Caldwell, a three-star general in charge of training Afghan troops, ordered the operation, Rolling Stone Magazine reported in a story published late on Wednesday.
An officer in charge of the unit objected when he was ordered to pressure the visiting senators and was harshly reprimanded by superiors, according to the magazine.
"My job in psy-ops is to play with people's heads, to get the enemy to behave the way we want them to behave," the officer, Lt. Colonel Michael Holmes, told Rolling Stone.
"I'm prohibited from doing that to our own people. When you ask me to try to use these skills on senators and congressman, you're crossing a line," he added.
Gen. David Petraeus has called for an investigation into charges, NBC News reported.
On the msnbc's "Morning Joe" program Thursday, NBC News Senior Pentagon Correspondent Jim Miklaszewski reported that officials both in Washington and Afghanistan had been "scrambling" to come up with a response to the allegations.
Miklaszewski also pointed out that using such tactics on U.S. citizens is against regulations and not to be done under any circumstances.
Among those targeted were senators John McCain, Joe Lieberman, Jack Reed, Al Franken and Carl Levin, as well as Representative Steve Israel of the House Appropriations Committee, the report said. The team also allegedly targeted Admiral Mike Mullen of the Joint Chiefs of Staff.
Levin pointed out Thursday that he has long been in favor of building up Afghan forces.
"For years, I have strongly and repeatedly advocated for building up Afghan military capability because I believe only the Afghans can truly secure their nation's future," Levin said in a statement. "I have never needed any convincing on this point. Quite the opposite, my efforts have been aimed at convincing others of the need for larger, more capable Afghan security forces, and that we and NATO should send more trainers to Afghanistan, rather than more combat troops."
'Very serious and disturbing'One of the lawmakers, Sen. Reed, told msnbc's Chris Jansing that he found the accusations "very serious and disturbing" and said the Pentagon should investigate, and if warranted, punish those involved.
The Rhode Island Democrat, who is a senior member of the Senate Armed Services Committee and a former U.S. Army Ranger, said he's been to Afghanistan 11 times and has tried to get a "broad view" of the situation on the ground by seeking out many different sources.
He said he never detected anything unusual when speaking to military personnel, but stressed that he weighs carefully what everyone has told him and doesn't put too much stock into any one individual.
According to Holmes, he and his four-man team arrived in Afghanistan at the end of 2009 in order to determine the effects of American propaganda on Afghans and the Taliban, the magazine reported.
Soon, though, Caldwell ordered the unit to gather profiles of visiting dignitaries, including their likes and dislikes and "hot-button issues," the magazine reported.
Holmes was asked how the general could secretly manipulate the lawmakers, Rolling Stone said.
"How do we get these guys to give us more people?" Caldwell asked, according to the magazine. "What do I have to plant inside their heads?"
U.S. law bars the military from using psy-ops on Americans, and every defense authorization bill explicitly prohibits the manipulation, the magazine reported.
"Everyone in the psy-ops, intel ... knows you're not supposed to target Americans," a veteran member of similar team told Rolling Stone. "It's what you learn on day one."