Clinton told U.S. lawmakers Wednesday that construction of the pipeline would be seen as a breach of American sanctions on Iran.
"We all know what the consequences of that are. And it would be particularly damaging to Pakistan, because their economy is already quite shaky," she said. "This additional pressure that the United States would be compelled to apply would further undermine their economic status. So we've been very clear in pointing out the consequences of pursuing such a pipeline."
The U.S. is committed to giving Pakistan $7.5 billion over five years to try and stabilize the government and win the support of its virulently anti-American people. Around $1 billion of that is earmarked for projects to boost energy supplies.
Brummitt reported from Islamabad.
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