Moore, who is a travel writer, editor-at-large for Germany's Spiegel Online and the author of "Sweetness and Blood," was kidnapped by 15 men Saturday en route to an airport in Somalia where he was researching a book on Somali pirates. An unspecified ransom has been demanded.
"We are aware of news reports that a U.S. citizen has been kidnapped in northern Somalia and we are concerned about the individual's safety and well-being," the State Department said in a statement.
"We have been in contact with the individual's family and we are working with contacts in Kenya and Somalia to ascertain further information."
President Mohammad Ahmed Alim of the autonomous Galmudug region of Somalia, where Moore was kidnapped, attempted to open negotiations with the pirates earlier this week, KTLA, Los Angeles, reported.
Moore's capture came just days before two aid workers were rescued from Somali captors in a U.S. military raid.