Before meeting their American counterpart Barack Obama, the Afghan and Pakistani presidents joined Hillary Clinton at the US State Department.
Clinton stressed her support for Hamid Karzai and Asif Ali Zardari, who the White House hopes can work together to beat the Taliban.
“Two very important leaders who are leading their countries at a difficult time in history, who are working hard to maintain and nurture democracy and who understand that we face a common enemy.”
Clinton also said the White House “deeply, deeply” regrets the death of Afghan civilians in US air raids.
Obama will meet both Zardari and Karzai separately to discuss among other things civilian and military aid, before a meeting of all three heads of state together.