CANBERRA: NATO still hopes to reopen transport supply routes to Afghanistan through neighbouring Pakistan despite securing new transit deals with three Central Asian states, NATO Secretary-General Anders Fogh Rasmussen said on Wednesday.

Pakistan banned trucks from carrying supplies to and from coalition troops in Afghanistan late last year in protest against a cross-border NATO air strike that inadvertently killed 24 Pakistani soldiers.

On Monday, the United States withdrew its team of negotiators from six weeks of talks with Pakistan without a new deal on re-opening the supply routes in a sign of deepening tension between the two uneasy allies in the war on militancy.

Rasmussen said the NATO transit agreements with Uzbekistan, Kazakhstan and Kyrgyzstan would give NATO forces more flexibility ahead of the planed withdrawal of most foreign combat troops from Afghanistan by the end of 2014.

"We want as many options as possible," Rasmussen told the National Press Club in the Australian capital, Canberra.

"Winding down a very comprehensive mission in Afghanistan is logistically quite a challenge, and to manage that we need as many transit opportunities as possible," he said.

However, Rasmussen also said officials were hopeful the transit route through Pakistan would be re-opened "in a not too distant future".

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The issue of military supply routes through Pakistan has become a lightning rod for tensions between the United States and Pakistan, adding to Pakistan's concerns over drone strikes and the U.S. incursion into Pakistan last year in the operation that killed al Qaeda leader Osama bin Laden.

U.S. officials have warned that resupplying troops in Afghanistan through the northern, Central Asian route could be up to two-and-a-half times more expensive.

That route could also require cooperation from Russia to ensure access to sea ports, but Rasmussen said NATO already had an agreement with Moscow. He gave few other details.

"We have already a reverse transit agreement with Russia, and the fact that we have now concluded transit arrangements with a number of Central Asian states makes our transit arrangement with Russia even more effective," Rasmussen said.

He refused to comment on the costs of using northern supply routes, adding the system worked on a commercial basis with transport companies in the transit countries.

Rasmussen is in Australia for talks with Australian Defence Minister Stephen Smith and to sign a NATO-Australia political agreement with Prime Minister Julia Gillard.

Australia, a strong U.S. ally, is the largest non-NATO contributor to Afghanistan, with around 1,500 troops. AGENCIES