By Chisa Fujioka and Yoko Kubota
TOKYO (Reuters) - Pakistan looks set to secure more than the $4 billion (2.7 billion pounds) in aid it has sought at a donor conference in Japan after Prime Minister Asif Ali Zardari vowed on Friday to step up the fight against militants.
In return for new promises of funds, Zardari assured donors, in comments that departed considerably from a prepared speech, that Pakistan would do its utmost to deliver on economic reforms and on fighting militants.
"Despite the fact that I lost the mother of my children, I have taken up this challenge ... to lead Pakistan out of these difficult times," said Zardari, the widower of assassinated former prime minister Benazir Bhutto.
"If we lose, you lose. If we lose, the world loses," he said.
The international community is worried an economic meltdown in Pakistan, propped up with a $7.6 billion loan from the International Monetary Fund over two years, could fan popular support for al Qaeda and other militant groups.
U.S. special envoy Richard Holbrooke told reporters that final pledges were likely to exceed the minimum $4 billion sought by Pakistan.
"I don't know the final figure, but it looks much higher than people expected," he told reporters.
Pakistan is central to U.S. 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.
Zardari gave a gloomy account of that situation.
"It is a terrain where no forces in the world or no armies of the world have never won before," he said. "War as it is not a 'win proposition'."
JAPAN IMPRESSED
Japanese Prime Minister Taro Aso, who met Zardari for talks on Thursday, said he was impressed by the president's resolve.
"I am convinced that the strong commitment by Pakistan itself will strengthen the resolve of the international community to support the civilian government," Aso told the gathering.
"We cannot stabilise Afghanistan without stabilising Pakistan and the opposite is also true," Aso added.
Iranian Foreign Minister Manouchehr Mottaki echoed that view.
"We feel and we believe that Pakistan is serious to combating against terrorism," he told reporters.
Speculation has simmered that Mottaki and U.S. special envoy Richard Holbrooke would have a chance to chat at Friday's gathering, but Holbrooke was coy when asked if they had spoken.
"We ran into each other," he told reporters.
Foreign investors are also eager to see Pakistan proceed with tough economic reforms seen as vital to restore growth.
"With the support of the IMF, the (World) Bank, and other development partners, Pakistan is now returning to a path that should allow for economic growth and poverty reduction," said Isabel Guerrero, World Bank vice president for South Asia.
"While it's been imperative to focus on the short term, in terms of regaining macroeconomic stability, we would not also want to undermine the importance of staying focussed on the longer- and medium-term priorities," she told the donors.
Pakistan has a wish-list of projects worth $30 billion that it wants to see implemented over the next 10 years, including hydro-electric dams, roads and projects aimed at improving security in its violence-plagued northwest on the Afghan border.
The United States announced on Friday that it would provide aid worth $1 billion over two years, subject to approval from Congress, matching a pledge from Japan.
(Writing and additional reporting by Linda Sieg; Editing by David Fox)
