Hundreds of containers of Canadian military equipment remain trapped in Afghanistan as the Pakistani government continues to refuse to reopen NATO supply lines into the country.

Thousands of tonnes of equipment including armoured vehicles, guns, ammunition and combat uniforms have already been airlifted out of the country. However, an estimated 400 containers remain stranded in secret locations throughout southern Afghanistan.

Pakistan closed NATO's main transit route from the port of Karachi in November following an air attack on the country's border that killed 24 Pakistani soldiers.

Supply trucks have sat idle in Afghanistan since then.

"It's engineering stores, it's spare parts, it's camp stores, defensive stores, things of that nature. This is equipment that we want to bring back to Canada," Brig.-Gen. John Mackay told CTV News.

Meanwhile, the port in Karachi, Pakistan is jammed with containers of equipment belonging to the U.S. and other NATO allies, waiting to be shipped to bases in Afghanistan.

Thousands of Pakistanis have rallied against the reopening of the NATO shipping routes. Anti-American sentiment is so strong in the country the government is afraid of the political backlash if the trucks are allowed through.

As a result, the U.S. has pulled its team of negotiators out of Pakistan.

"The teams themselves have taken it as far as we can right now," said Capt. John Kirby, U.S. deputy assistant secretary of defence. "And it's in the hands of the political leadership in Pakistan.

Pakistan is demanding NATO pay $5,000 a truck, a significant hike from the old rate of $200 a truck.

Defence Minister Peter MacKay said Canada is working with NATO allies in hopes of retrieving the Canadian Forces equipment.

"We are working with our allies to try to persuade Pakistan to be more co-operative when it comes to supply of the mission and when it comes to the return of certain equipment," MacKay said.

With a report from CTV's Ottawa Bureau Chief Robert Fife