''It is with a profound sense of sadness and regret that we announce the loss of two locally employed staff who were kidnapped in May and killed at the hands of violent extremists,'' US Ambassador to Iraq Ryan Crocker said in a statement.
A US official, who spoke on the condition on anonymity, said the couple were Hazim Hanna and his wife Enel Meskoni.
Their identities were confirmed through fingerprint records.
Hanna went missing first and when Meskoni went to look for him, she was abducted as well, US officials said at the time of their disappearance.
Al Qaeda-led militant group Islamic State in Iraq claimed responsibility for their slaying in a message posted on a Web site on May 31. It implied their throats had been slit.
''We will work with the government of Iraq to relentlessly pursue those responsible,'' Crocker said.
Kidnapping and killing have become a commonplace risk of living in Baghdad since the US-led invasion to topple Saddam Hussein, with tens and sometimes scores of mutilated bodies dumped on the streets of the capital every day.
Many are the victims of sectarian tit-for-tat killings between majority Shi'ite and minority Sunni Arabs. But anyone employed by the US authorities lives in particular peril.
REUTERS GL KP1414