A U.S. terrorism watchdog says al-Qaida's affiliate in Yemen is threatening to kill an American hostage kidnapped in the Arabian Peninsula country over a year ago if its demands are not met.

The SITE Intelligence Group, which monitors terror sites, said Thursday it obtained a video by Yemen's al-Qaida offshoot featuring the hostage identified as 33-year-old Luke Somers, an American British-born photojournalist.

Somers was kidnapped in the Yemeni capital, Sanaa, in September 2013.

The three-minute video released by SITE first shows Nasser bin Ali al-Ansi, a local al-Qaida figure, speaking about alleged American crimes against the Muslim world and saying the U.S. is "aware" of the militants' demands.

Then Somers gives a brief statement in English, saying he is certain his "life is in danger" and asking for help.