Security analysts in the United States say U.S. and NATO forces in Afghanistan are not likely to defeat the Taliban and other insurgent groups on their own.

Experts from RAND Corporation issued a paper Tuesday saying the international community must step up efforts to foster relationships with Afghan tribes and local organizations.  They also say international partners have not demonstrated a solid commitment to Afghanistan.

The report's authors stress that Washington must recognize that Afghanistan's central government is weak.  

The paper, commissioned by the United States Institute of Peace, also says additional U.S. troops should focus on mentoring Afghan security forces.  

President Barack Obama said Tuesday the conflict in Afghanistan cannot be solved by military means alone.  In an interview with the Canadian Broadcasting Corporation, the president said "we're going to have to use diplomacy, we're going to have to use development."

Mr. Obama also said a strategic review of U.S. policy is underway and will be released soon.

The U.S. commander in Afghanistan, General David McKiernan, has requested up to 30,000 additional troops, including combat and aviation brigades, to join U.S. military units already in the country.

White House Press Secretary Robert Gibbs told reporters aboard Air Force One Monday that the decision about troop levels will be made within days, not weeks.

There are about 60,000 foreign soldiers in Afghanistan, most of them part of the International Security Assistance Force.

Some information for this report was provided by AFP, AP.