Speaking at the Senate Appropriations Panel today, Secretary of Defense Leon Panetta discussed the closed border with Pakistan, saying it is costing the US an additional $100 million every month to use alternative supply routes through the north.

The comments were in the context of a discussion of whether or not to cut yet more planned aid to Pakistan. Panetta warned against a full cut but encouraged the US to place conditions on the continued delivery of $3.5 billion in aid to Pakistan this year.

Pakistan closed the border in November after a US attack killed 24 Pakistani soldiers, and its parliament has conditioned reopening the border on the US apologizing for the killings and also promising to end drone strikes. The US has ruled out doing either, and yesterday US officials say Pakistan should just “bite the bullet” and accept reopening the route without any concessions.

Pakistan’s military was authorized to negotiate a settlement, and raised the prospect of simply changing more for the NATO trucks to cover the cost of security. The US condemned this as price gouging, though Panetta’s comments today suggest it would be much cheaper than the alternative.

Foreign Minister Hina Khar rejected the idea that this was “price gouging” and said Pakistan had been clear about what was needed from the US to reopen the border. The US withdrew its negotiators earlier this week, saying talks had stalled.