A Canadian woman being held hostage in Pakistan says time is running out and her militant captors will behead her soon if a ransom isn't paid.

Vancouver's Beverly Giesbrecht, who converted to Islam and is now known as Khadija Abdul Qahaar, has been held since November.

The independent journalist was kidnapped at gunpoint while doing freelance work for the Al Jazeera Arab network, in a tribally ruled region of northern Pakistan.

"We have very short time now. I am going to be killed at any time as you can see the dagger," she says in the video, referring to a knife hung on the wall behind her.

Giesbrecht's captors have demanded a ransom and the release of Taliban prisoners, in exchange for her return.

According to some reports, the Taliban will free her for US$375,000 in ransom.

The 52-year-old pleads for her life in the video, saying her fate will be the same as Piotr Stanczak, a Polish engineer who was executed last month.

"I am going to be beheaded just like the Polish engineer, probably by the end of the month. The deadline is by the end of March, and that's basically, I don't know, 18 days or 16 days," she says, closing her eyes.

"I'm not quite sure how long that is but the time is very short and my life is going to end."

The short video was sent to The Globe and Mail.

In it, Giesbrecht is wearing a head scarf and sitting on a wooden chair. She explains she is being held by the Taliban somewhere near the border of Afghanistan, but isn't sure which of the two countries she is being held in.

Security expert Eric Margolis said there have been other similar cases in recent months, including that of Stanczak, and Giesbrecht isn't exaggerating when she says her life is in danger.

"It's being done for one of two reasons," he told CTV's Canada AM.

"First there are criminal gangs everywhere and they may have done this for money. It has also been reported there have been ransom demands. Also it's been said they have offered to trade her for hundreds of Taliban prisoners who are being held by the Afghan government."

Canada's Foreign Affairs Department has declined to comment on Giesbrecht's plight, but Margolis said officials are likely working behind the scenes with the Pakistan government.

He said it is "totally out of character" for tribes in the region to kidnap a woman, since their code of honour forbids the mistreatment or murder of women.

Giesbrecht converted to Islam after the terrorist attacks of Sept. 11, 2001.

She runs a website called Jihad Unspun, which claims to provide information that is "devoid of the constraints of mainstream media."