Donors pledged more than $US5 billion in new aid over the next two years to cash-strapped Pakistan on Friday after President Asif Ali Zardari promised to fight militancy destabilising the nuclear-armed country.
Nearly 30 donor countries, as well as international organisations, met in Tokyo to help Pakistan stabilise its economy amid fears that financial woes could lead to increased support for militant groups.
The international community is worried an economic meltdown in Pakistan, propped up with a $US7.6 billion loan from the International Monetary Fund over two years, could fan popular support for al Qaeda and other militant groups.
Pakistan is central to United States President Barack Obama's plan for South Asia, which includes trying to stabilise Afghanistan where Taliban militants - many operating from lawless enclaves in northwest Pakistan - have thrown that effort into doubt.
The United States and Japan each pledged $US1 billion, the BBC reports.
Japanese Prime Minister Taro Aso has said that ensuring stability in Pakistan is key in the fight against terrorism in the southwest Asia region.
"Without stability in Pakistan, there is no stability in Afghanistan either," Mr Aso said when opening the conference.
Pakistan's President Asif Ali Zardari spoke of his fear that the world does not fully realise the extent of threats facing his country.
"We are willing to fight. Despite the fact that I lost the mother of my children, I have taken up this challenge," said Mr Zardari, the widower of assassinated former Prime Minister Benazir Bhutto.
"I am hoping, and with all humility, asking of the world to help us fight this tremendous challenge, which not only do we face, but it doesn't end on my border," he said. "If we lose, you lose. If we lose, the world loses."
The donors' meeting is supported by the World Bank and attendees include China and Saudi Arabia.
The US pledge of $1 billion was described as a down-payment on the previously announced $1.5 billion already promised to Pakistan for each of the next five years.
However, Pakistan has resisted international pressure to tax the small landowning elite where most political power resides.
Economic growth is expected to slow to between 2.5% and 3.5% for the year to June 2009, a rate considered too slow to find jobs for Pakistan's population of 170 million.