He said the Taliban, which was driven from power by the US-led invasion of Afghanistan in 2001, were "a force that is acting in cowardice by killing children".
"Cold blooded killers"
Bush called the Taliban "cold blooded killers" who "have no regard for human life" and put a positive spin on Afghanistan's progress since the 2001 invasion.
"There is still work to be done, don't get me wrong," he said. "But progress is being made, Mr President, and we're proud of you."
Dr Marvin Weinbaum, a professor at the Middle East Institute in Washington, told Al Jazeera: "It is in both their interests to play up the positives and I think that's really all that this meeting was intended to do."
But while the two leaders blamed Afghanistan's problems on the Taliban,
both leaders have come under fire over the rising number of civilian deaths in Afghanistan.
The growing toll has inflamed public opinion in the country and increased hostility towards foreign troops.
Karzai's critics say he has failed to address both the increasing civilian deaths caused by foreign forces and a decrease in security across the country.
Bush's critics, on the other hand, say the US president has neglected Afghanistan after ordering the invasion of Iraq in 2002.
Weinbaum said that Karzai's support might well be strongest in America rather than in Afghanistan.
"If he [Karzai] has a really strong constituency it's here in the United States," he said.
Difference of opinion
|Karzai's critics say he has failed to address the |
growing civilian death toll in Afghanistan [AFP]
The two leaders differed over Iran's influence in Afghanistan. Karzai had said in advance of his visit to Camp David that Iran is a partner in the fight against terrorism and narcotics.
"So far, Iran has been a helper," he said over the weekend.
But Bush, whose administration has been sharply critical of Iran, said: "I would be very cautious about whether or not the Iranian influence there in Afghanistan is a positive force."
The meeting was also been overshadowed by the US failure to find Osama bin Laden, the al-Qaeda leader, who US intelligence officials say is hiding across Afghanistan's border in Pakistan's tribal region.
Bush has said before that he would order the US to act inside Pakistan if there were firm intelligence on the whereabouts of bin Laden.
Pakistan's leaders, though, have objected to any unilateral action by Washington. In their meeting Bush and Karzai also discussed the fact that Afghanistan now accounts for 95 per cent of the world's poppy production, which is used to make heroin.
Karzai finished the press conference, saying: "We know today that the terrorists are buying and selling suicide bombers. We have received calls in our government offices by handlers of suicide bombers that they want to sell them to us. So it's become a trade."
There was no mention of the crisis involving 21 South Korean hostages seized by the Taliban in July.
The kidnappers have killed two of the 23 initially taken and are demanding the release of Taliban prisoners in exchange for the rest of the group.
South Korea has appealed to the US and the Afghan officials to negotiate the release, but Bush and Karzai have both said that they will not make concessions to the Taliban that might encourage a hostage-taking "industry".