(AP) -- Commonwealth government leaders meeting in Australia agreed Saturday to step up efforts to eradicate polio worldwide, despite the Afghanistan war setting back vaccination efforts there and in neighboring Pakistan.
Leaders of Britain, Canada, Australia and Nigeria, as well as billionaire philanthropist Bill Gates, committed tens of millions of dollars in additional funding toward the World Health Organization's campaign to wipe out the disabling disease from the four countries where it remains endemic - India, Afghanistan, Pakistan and Nigeria.
All the polio-endemic countries except for Afghanistan are represented at the three-day summit in the western Australian city of Perth. The summit comprises the leaders of 53 countries, most of them former British colonies.
Pakistani Prime Minister Yousuf Raza Gilani said he was "seriously concerned" that polio infection rates had worsened in his country in recent years.
Pakistan was the only country in the world to increase reported polio infections last year. There were 144 cases in 2010, up from 89 in the previous year, according to WHO figures. So far this year, 118 cases have been reported in Pakistan - the largest number of any country.
Gilani blamed the flow of people fleeing fighting on both sides of the Afghanistan-Pakistan border, the inaccessibility of war zones to medical teams and religious "fanatics" opposed to vaccines for the failures of vaccination programs in the border regions.
But Pakistan's government remains committed to a target of eliminating polio by the end of this year, he said.
"No doubt we have a huge task ahead, but we remain determined to eradicate this and protect every child in Pakistan from the scourge of polio," Gilani told reporters.
In neighboring Afghanistan, polio infections have jumped from 30 last year to 41 so far this year.
British Prime Minister David Cameron said nations cannot accept the current situation where the world is only 99 percent polio free.
"If we fail to get rid of polio completely, we run the risk that the disease will spread back to countries where it's been eliminated," Cameron said.
Britain had already doubled its contribution to the 23-year-old WHO Global Polio Eradication Initiative for this year and 2012 when it announced in January an additional 40 million pound ($65 million) contribution.
Australia, which put polio on the Commonwealth meeting agenda, promised an addition 50 million Australian dollars ($54 million).
Gates used a video message to the Perth meeting to pledge an extra $40 million from the Bill & Melinda Gates Foundation. He warned that the campaign to eliminate polio forever was at a crossroads, saying recent cases in China demonstrated the risk of a polio resurgence.
China had been free of the paralytic disease for 11 years before an outbreak in the country's far western region that has paralyzed 17 people since July, killing one of them.
WHO said the polio strain detected in China traveled from neighboring Pakistan.
Canadian Prime Minister Stephen Harper also pledged increased funding to polio surveillance, but did not specify an amount.
Harper said polio eradication was a key priority of the Canadian mission in Afghanistan. He said 85 percent of Afghanistan was polio free.
Nigerian President Goodluck Jonathan said his government's increasing its funding for polio vaccinations in the African nation from $17 million to $30 million annually should result in the disease disappearing by the end of 2012.
Nigeria has recorded 49 cases so far this year - one more than all of 2010.
India recorded 44 cases in 2010, but this year has reported a single case, in January.