DUBAI (AFP) - Al-Qaeda in Yemen has threatened to execute a US journalist taken hostage last year, who called for help in a video released by the extremist group, SITE Intelligence reported Thursday.

In the video dated December 2014, the hostage said his name was Luke Somers, 33, and that he was kidnapped more than a year ago in Sanaa.

Somers said he was looking for help and that his life was in danger.

The photojournalist was kidnapped in the Yemeni capital in September 2013, the US-based monitoring agency said citing reports.

The video features a message by Nasser bin Ali Al-Ansi, of Al-Qaeda in the Arabian Peninsula (AQAP), threatening to kill him three days "after the issuance of this statement" if Washington failed to meet the group's demands.

"Otherwise, the American hostage held by us will meet his inevitable fate," he said, without elaborating on the demands.

AQAP is considered by Washington as the most dangerous affiliate of Al-Qaeda.

A Yemen defence ministry website said last week that Al-Qaeda moved hostages including an American journalist, as well as a Briton and a South African days before a raid in southeastern Hadramawt province to free him.

Yemen is a key US ally in the fight against Al-Qaeda, allowing Washington to conduct a longstanding drone war against the group on its territory.

The militant group has exploited instability in the impoverished country since a 2011 uprising overthrew president Ali Abdullah Saleh.