NATO's secretary-general says he's optimistic that the international community will continue to finance the Afghan security forces.
"This summit is not a pledging conference, but nevertheless a number of countries have announced substantial contributions to the Afghan security forces, so I'm optimistic," Anders Fogh Rasmussen told CNN's "State of the Union" on Sunday.
The international community in general has a responsibility and interest in ensuring the Afghan forces take full responsibility for security after 2014 so that terrorist safe havens aren't reestablished, the NATO chief said.
Pledges for about a third of that have been announced by Australia and European nations. U.S. taxpayers and some nations outside the military coalition likely will make up the $2.3 billion difference.
The NATO summit opens Sunday in Chicago. President Barack Obama is expected to meet with Afghan President Hamid Karzai on the summit's sidelines to discuss planning for Afghanistan's 2014 elections and the prospect of a political settlement with the Taliban. NATO's plans keep foreign forces in Afghanistan through the 2014 election but exiting the country by 2015.
Fogh Rasmussen pointed to Afghanistan as an example of NATO interests lying beyond the alliance countries' borders more frequently in the future.
"We are in Afghanistan prevent the country from once again becoming a safe haven for terrorists, who can use that safe haven as a launching pad for terrorist attacks against Europe and North America," he said. "So though territorial defense remains the core task of NATO, we realize that defense of our borders may well start far from our borders in today's world."