An Indian-American lobbying group, the World Bank, the International Monetary Fund and US presidential candidates joined the world's outpouring of condemnation over the assassination of Pakistan opposition leader Benazir Bhutto.
World Bank president Robert Zoellick said on Thursday he was "shocked and saddened", adding: "This tragedy will only hinder Pakistan's critical agenda of meeting the urgent needs of its many citizens".
The powerful US-India Political Action Committee (USINPAC), which represents 2.5 million members, expressed condolences to the people of Pakistan for Bhutto's murder, which it called an act of "political violence and militant extremism".
Michael Taylor, USINPAC's director of government affairs, noted Pakistan's role on the "forefront of the US-led war" on terrorism and said the Indian-American community remained "watchful of the actions taken by our government in this matter".
Dominique Strauss-Kahn, IMF director, called the news "shocking".
Hillary Clinton, the leading Democratic candidate for the US presidential nomination who knew Bhutto personally, said the Pakistani leader had made the "ultimate sacrifice".
"Her death is a tragedy for her country and a terrible reminder of the work that remains to bring peace, stability, and hope to regions of the globe often paralysed by fear, hatred, and violence," Clinton said in a statement.
Clinton's chief rival, Barack Obama, said the US would stand with the Pakistani people "in their quest for democracy and against the terrorists who threaten the common security of the world".
Former New York mayor Rudy Giuliani, who presided over a city shocked by the 2001 terrorist attacks, called for a redoubling of efforts to win the war against terrorism.