Islamabad, Pakistan (CNN) -- Intense rain and gushing flood waters threatened Wednesday to cause more misery in monsoon-bloated Pakistan, where 3 million people are already suffering. U.S. Secretary of State Hillary Clinton urged Americans to donate to relief efforts, saying that experience in post-earthquake Haiti showed that small donations can make a big difference. Pakistani Prime Minister Yousuf Raza Gilani appealed to residents to curtail expenditures for Ramadan feasts and upcoming independence day celebrations and contribute instead to help their desperate compatriots. As many as 1,500 people have died in Pakistan's worst flooding in 70 years. Relief agencies were struggling to reach people who have lost everything to walls of water. Many were cut off after roads and bridges washed away.
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NEW: Secretary of State Hillary Clinton appeals for aid
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NEW: Clinton says the crisis aid is essential part of building ties with Pakistan
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About 3 million people have been affected by monsoon rains and flooding
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Some Pakistanis say their government has been slow to respond
In a special emergency meeting Wednesday, @placeholder said the government was doing all it could to address the crisis.