A senior U.S. defense official confirmed to the Associated Press on Wednesday the U.S. citizen killed was a CIA officer. Agency officials declined to comment.
However, a U.S. official told The Hill on Wednesday the individual was a civilian member of the U.S. government working alongside American forces at the Village Support Platform in southern Afghanistan where the attack occured.
"An investigation into the incident is ongoing, and although all possible motivations for the attack are being investigated, no further details are available at this time," the official said.
“The US official killed in the suicide bombing was one of many civilians in Afghanistan who bravely serve alongside our armed forces. He will be sorely missed," the official added.
Both Americans were among the six individuals killed during the attack on an Afghan intelligence outpost in the Maruf district of Kandahar province in southern Afghanistan last Saturday, according to recent news reports.
The reported death of the CIA operative was the latest known agency casualty in Afghanistan since seven CIA officers were killed in by a Taliban suicide bomber in Khost province in 2009.
“Throughout our history, the reality is that those who make a real difference often face real danger," then CIA Director Leon Panetta said at the time of the 2009 strike.
Last Saturday's insider attack was also the first alledgedly carried out by a member of Afghanistan's nascent intelligence directorate, known as the National Directorate of Security.
Afghan and U.S. military officials were conducting a visit to the Afghan intelligence post when, during the visit, an Afghan intelligence officer detonated explosives he had concealed beneath his uniform, killing himself and six others.
Also among the dead was Ghulam Rasool, the Afghan deputy director of intelligence for Kandahar province, along with two of his bodyguards and another Afghan intelligence officer, according to the New York Times.
But on Tuesday, Shafiqullah Tahiri, a spokesman for Afghanistan's National Security Directorate, told reporters that any claims suggesting an Afghan intelligence officer carried out the attack were baseless.
While Tahiri noted the bomber was wearing an Afghan intelligence agency uniform at the time of the attack, he claimed the attacker somehow obtained the uniform to gain access to the Maruf facility.
The attack comes just as U.S. and Afghan intelligence officials are ratcheting up efforts to purge Taliban infiltrators from the ranks of the Afghan National Security Forces.
Afghanistan's military and intelligence leaders had been busily planting dozens of intelligence officers within the military and national police forces across the country to ferret out Taliban operatives or sympathizers.
But prior to last Saturday's suicide strike, the threat of an insider attack had come mostly from Afghan military and police, not its intelligence officers.
This story was updated at 1:19 p.m.