The United States executed a secret operation in Yemen that aimed at, but was unable to kill, an Iranian military ,official last week, US officials told Reuters.
The attack was conducted on the same day that the US assassinated Qassem Soleimani in a drone attack in Baghdad, the officials said.
The timing could show that the United States had sought to take out a wider swathe of the Iranian army leadership when they killed Soleimani, citing an impending threat from them.
The Pentagon refused to make a statement on the failed strike in Yemen, first reported by the Washington Post.
"The Department of Defense does not discuss alleged operations in the region," Pentagon spokeswoman Commander Rebecca Rebarich said.
One of the US official named the Iranianwho had been singled out as Abdul Reza Shahlai, a senior officer in elite Quds force, the unit in charge of foreign operation that had been headed by Soleimani.
The U.S. Treasury Department says he was based in Yemen and charged him of "a long history of targeting Americans and U.S. allies globally," which included killing of U.S.-led coalition forces in Iraq. It has offered a $15 million reward in connection with him under its "Rewards for Justice" programme.
The US has accused Shahlai of coordinating a failed 2011 plot to assassinate Saudi Arabia's ambassador to the United States at a cafe in a posh neighbourhood of the U.S.
"Shahlai approved financial allotments ... to help recruit other individuals for the plot, approving $5 million as payment for all of the operations discussed," the Treasury Department said.
President Donald Trump on Thursday stated that US killed Soleimani in part because "they were looking to blow up our embassy." "And he had more than that embassy in mind," Trump said.
It was uncertian if Shahlai may have been part of that broader plot.
In response for killing Soleimani, Iran fired missiles on Wednesday at bases in Iraq where U.S. troops were based.