Secretary of State Condoleezza Rice met on Monday with Pakistani Foreign Minister Khurshid Kasuri and discussed the continuing problems along the Pakistani-Afghan border.
That same issue dominated Rice's travels to the two countries in late June.
State Department spokesman Sean McCormack said Rice reaffirmed that both Afghanistan and Pakistan have a shared interest in the stability and the security of each other's states.
"The Afghans have an interest in a stable, more prosperous, more secure Pakistan, and vice versa," he said.
"Pakistan has an interest in an Afghanistan that is stable, that is secure, and that prospers economically."
Both have an interest in building up economic ties extending from Central Asia through Afghanistan and Pakistan into India, McCormack said.
"Part of realizing the full potential of that economic integration is the common fight against terrorism," he said. "I think that the Pakistani government understands that, as well as the Afghan government.
McCormack added that the United States hopes to enhance the Afghan-Pakistani partnership "in fighting what ultimately is a common destabilizing enemy."
On another subject, he indicated that the United States had no objection to India's decision to undertake a missile test on Monday.
"They did notify us in advance that they were doing this," McCormack said. "They did notify the Pakistan government that they were doing it in advance, in conformity with their agreement with the Pakistani government."
It would be wrong, he said, to treat the Indian test in the same category as the North Korean missile launches last week.
"I wouldn't try to draw any equivalence between India, the world's largest multiethnic democracy, and the North Korea, a closed totalitarian state," McCormack said, reports AP.
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