International aid agency Oxfam on Saturday urged US President Barack Obama to forge a new plan for Afghanistan to avert a major crisis at a "critical juncture" for the country.
Security is plummeting and around five million Afghans, out of an estimated population of around 30 million, are struggling to meet immediate food needs, the charity said in a statement.
"With spreading insecurity and civilians facing critical needs, there must be a comprehensive new strategy which will avert a major crisis," Oxfam America president Raymond Offenheiser said.
The relief group said it sent a memo to Obama, who took office on January 20, raising concerns "that events have reached a critical juncture in Afghanistan."
The United States has 36,000 troops in Afghanistan and is planning to boost its forces by up to another 30,000 in the next 12 to 18 months.
Oxfam said "conditions could deteriorate further unless the United States takes a lead in addressing failures in governance, aid and reconstruction, and protecting civilians."
This required looking beyond military solutions to the growing violence, Oxfam said.
The United States is the lead provider of billions of dollars in aid and tens of thousands of troops on which Afghanistan depends to fight a Taliban-led insurgency as it attempts to rebuild after decades of war.
But security has massively deteriorated and last year reached its lowest point since the United States led the 2001 invasion that drove out the Taliban regime and installed a Western-backed government.
In 2008, a hike in deadly insurgent attacks and scores of civilian casualties from international military operations stoked anger among an impoverished people exhausted by war and foreign intervention.
The number of civilians who have lost their lives in the conflict is disputed by all sides, including the Taliban and the international forces.
Oxfam put it at 2,000 last year, including nearly 800 who died from operations waged by international and Afghan government forces.
The United Nations has access to only half the country, and rising attacks on aid workers hampered the delivery of aid, the international charity said.
Its memo included calls for a better humanitarian response to the crisis, improvements in using aid effectively, more support for agriculture and the rural economy, and new measures to protect civilians.