Al-Qaeda's branch in Yemen has threatened a British-born American hostage kidnapped over a year ago, giving Washington three days to meet unspecified demands and denouncing US actions in the Arabian Peninsula country.

In a new three-minute video posted on Twitter account of al-Qaeda in the Arabian Peninsula (AQAP) on Thursday, the hostage was identified as 33-year-old freelance journalist Luke Somers who gave a somber statement in English, asking for help.

"It's now been well over a year since I've been kidnapped in Sanaa," Somers said. "Basically, I'm looking for any help that can get me out of this situation. I'm certain that my life is in danger. So as I sit here now, I ask, if anything can be done, please let it be done. Thank you very much."

Before Somers' statement, the video showed AQAP commander Nasser bin Ali al-Ansi, reading in Arabic and speaking about alleged American "crimes against" the Muslim world.

Al-Ansi criticised US-led airstrikes against the Islamic State of Iraq and the Levant (ISIL) and President Barack Obama for his "latest foolish action", referring to the "failed operation" in Hadramawt. He said an "elite group of mujahedeen", or holy warriors, were killed in the US raid.

He also warned the US against more "stupidities", referring to future attempts to rescue hostages.

Al-Ansi gave the US three days to meet AQAP's demands or "otherwise, the American hostage held by us will meet his inevitable fate", without elaborating or explicitly saying they would kill their captive.

Al-Ansi also did not specify the group's demands, but said Washington was "aware" of them.

Kidnapped journalist

Somers was kidnapped in September 2013 from a street in the Yemeni capital, Sanaa, where he had worked as a freelance journalist for the Yemen Times.

Since his capture, Yemeni journalists have been holding sit-ins in Sanaa to press the government to seek his release.

Somers was likely among a group of hostages who were the objective of a joint rescue mission by US operation forces and Yemeni troops last month that freed eight captives in a remote corner of Yemen's Hadramawt province.

At the time, a Yemeni official said the mission, carried out in a vast desert area dotted with dunes called Hagr al-Saiaar, an al-Qaeda safe haven not far from the Saudi border, failed to liberate five other hostages. Among them were an American journalist and a Briton who were moved elsewhere by their al-Qaeda captors days before the raid.

The American was not identified by name and Yemen did not officially confirm the participation of US commandos in the rescue mission - a rare instance of US forces intervening on the ground in Yemen.

Al-Qaeda in the Arabian Peninsula, as the Yemeni group is known, is considered by the US to be the world's most dangerous branch of the terror network and has been linked to several failed attacks on the US territory.

Source: AP