Updated 11:29 PM ET
(CBS/AP) TOKYO - International donors pledged Sunday $16 billion in badly needed development aid for Afghanistan over the next four years when most foreign troops will leave as Afghan President Hamid Karzai urged the international community not to abandon his country.
The major donors' conference, attended by about 70 countries and organizations, is aimed at setting aid levels for the crucial period through and beyond 2014, when most NATO-led foreign combat troops will leave and the war-torn country will assume responsibility for most of its own security.
"I request Afghanistan's friends and partners to reassure the Afghan people that you will be with us," Karzai said in his opening statement.
Japanese foreign minister and U.S. officials traveling with Secretary of State Hillary Rodham Clinton said the donors have made $16 billion available through 2015, which would be in line with the nearly $4 billion per year that the Japanese co-hosts had said they were hoping to achieve during the one-day conference.
Japan, the second-largest donor, says it will provide up to $3 billion through 2016, and Germany has announced it will keep its contribution to rebuilding and development at its current level of $536 million a year, at least until 2016.
But the donors are also expected to set up review and monitoring measures to assure the aid is used for development and not wasted by corruption or mismanagement, which has been a major hurdle in putting aid projects into practice.
"We have to face harsh realities filled with difficulties,"' said Japan's Prime Minister Yoshihiko Noda.
Afghanistan has received nearly $60 billion in civilian aid since 2002. The World Bank says foreign aid makes up nearly the equivalent of the country's gross domestic product.
Foreign aid in the decade since the U.S. invasion in 2001 has led to better education and health care, with nearly 8 million children, including 3 million girls, enrolled in schools. That compares with 1 million children more than a decade ago, when girls were banned from school under the Taliban.
Improved health facilities have halved child mortality and expanded basic health services to nearly 60 percent of Afghanistan population of more than 25 million, compared with less than 10 percent in 2001.
But the flow of aid is expected to sharply diminish after international troops withdraw, despite the ongoing threat the country faces from the Taliban and other Islamic militants.
Along with security issues, donors have become wary of widespread corruption and poor project governance. Before the conference, Japanese officials said they were seeking a mechanism to regularly review how the aid money is being spent, and guarantees from Kabul that aid would not be squandered.
The U.S. portion is expected to be in the decade-long annual range of $1 billion to this year's $2.3 billion. Officials declined to outline the future annual U.S. allotments going forward, but the Obama administration has requested a similarly high figure for next year as it draws down American troops and hands over greater authority to Afghan forces.
The Obama administration will ask Congress to sustain U.S. assistance for Afghanistan near the average amount it has been over the last decade through 2017 as part of the international effort to stabilize the country even as most international forces pull out over the next two years. Secretary of State Clinton made the pledge Sunday.
The U.S. funds will help Afghanistan build its economy and make necessary reforms, Clinton said.
"We have to make the security gains and the transition irreversible," Clinton told officials, including Karzai.
She said Afghan security "cannot only be measured by the absence of war."
"It has to be measured by whether people have jobs and economic opportunity; whether they believe the government is meeting their needs."
Clinton said Afghanistan has made substantial progress over the last decade, but needs effective collaboration between its government, private sector, neighbors and international donors "so that this decade of transformation can produce results."
Clinton said the aid request to Congress through 2017 would be to maintain funding at or near the average level, without specifying further.
The total amount of international civilian support represents a slight trailing off from the current annual level of around $5 billion, a number somewhat inflated by U.S. efforts to give a short-term boost to civilian reconstruction projects in Afghanistan, mirroring President Barack Obama's decision in 2009 to ramp up military manpower in the hopes of routing the Taliban insurgency.
The aid is intended nevertheless to provide a stabilizing factor as Afghanistan transitions to greater independence from international involvement.
But it will come with conditions. The pledges are expected to establish a road map of accountability to ensure that Afghanistan does more to improve governance and finance management, and to safeguard the democratic process, rule of law and human rights especially those of women.
Karzai vowed to "fight corruption with strong resolve." But he still faces international weariness with the war and frustration over his failure to crack down on corruption.
Clinton, who briefly visited the Afghan capital on Saturday before heading to Tokyo, had breakfast with Karzai and acknowledged that corruption was a "major problem."
The $4 billion in annual civilian aid comes on top of $4.1 billion in yearly assistance pledged last May at a NATO conference in Chicago to fund the Afghan National Security Forces from 2015 to 2017.