Iran offered the Taliban bounties to attack US and coalition soldiers in Afghanistan, just as Russia allegedly did, CNN reported Monday citing US military intelligence.
CNN said the US identified payments tied to six attacks last year, including an attack in December on a building outside Bagram Air Base near Kabul.
The attack, which CNN said killed two Afghan civilians and left four Americans injured, brought US-Taliban peace negotiations to a temporary halt.
In a statement the US Department of Defense would not confirm or deny the CNN report.
Major Rob Lodewick, a Pentagon spokesman, said they do not disclose details of internal discussions on intelligence.
However, he added, the department "has repeatedly demanded, both publically and privately, that Iran cease its scourge of malign and destabilizing behavior throughout the Middle East and the world."
"Iran's inimical influence seeks to undermine the Afghan peace process and foster a continuation of violence and instability," he added.
In June US media reported that intelligence had determined that Russia had offered the Taliban bounties to kill US soldiers in Afghanistan.
The report was not denied by top officials, and was characterized by some as based on inconclusive information.
But it became a political issue after the White House was questioned and President Donald Trump denied he had ever been briefed about the allegations.