Munter made the remark during a visit to the volatile northwestern Pakistan city of Peshawar, not far from the Afghanistan border.
His visit came as the Pakistani parliament on March 20 began a debate about the future of Pakistani ties with Washington, after months of severely strained relations.
Munter said the United States wants to reach a deal with Pakistan on the reopening of ground supply routes from Pakistan to NATO-led forces in Afghanistan.
The routes were shut after the November NATO air attack that killed 24 Pakistani soldiers.
That bloodshed, and other issues, led to a sharp deterioration in ties between the Pakistani government and Washington.