US and Yemeni forces recently tried unsuccessfully to rescue an American journalist held by Al-Qaeda, which has now threatened to execute him, officials said Thursday.

US and Yemeni forces recently tried unsuccessfully to rescue an American journalist held by Al-Qaeda, which has now threatened to execute him, officials said Thursday.

President Barack Obama last month approved the rescue operation to free a number of hostages, including US national Luke Somers, held by Al-Qaeda in Yemen, the White House and the Pentagon said.

"Regrettably, Luke was not present, though hostages of other nationalities were present and were rescued," National Security Council spokesperson Bernadette Meehan said in a statement.

Al-Qaeda in Yemen released a video earlier Thursday threatening to execute the American photojournalist, who was abducted last year in the Yemeni capital.

The details of the operation remained classified but the government decided "to provide accurate information given that it is being widely reported in the public domain," Pentagon press secretary Rear Admiral John Kirby said.

A Yemen defense ministry website had said last week that Al-Qaeda had moved hostages -- including Somers, as well as a Briton and a South African -- days before the rescue operation in southeastern Hadramawt province.

The New York Times earlier reported American special operations forces found eight other hostages in the raid but not Somers.