The United States and Afghanistan should develop a joint plan to replace private security guards gradually rather than enforce a ban, U.S. Secretary of State Hillary Clinton said on Saturday.
State Department spokesman P.J. Crowley said Clinton telephoned Afghan President Hamid Karzai "to offer ideas" on his decision to ban all private security contractors from December.
Clinton "suggested building a joint plan to steadily replace contractors while managing the impact on existing operations," Crowley said in a message on Twitter.
"Clinton pledged to work cooperatively to support a smooth transition to full Afghan security responsibility," Crowley said.
U.S. media reports have said the proposed security guard ban could imperil about $1.5 billion in reconstruction work, including projects key to NATO's counterinsurgency strategy in the Afghan war.
The private security firms have become a point of friction because some have been involved in high-profile shootings and other incidents.
A U.S. Senate inquiry into private security contracting in Afghanistan concluded this month that funds had sometimes been funneled to warlords.
Karzai issued a decree in August banning all private security contractors in Afghanistan within four months.
Thousands of private security contractors guard everything from U.S. military bases to embassies.
Karzai modified his decree last week, agreeing to permit private security guards to protect embassies, military bases and depots, diplomatic residences and the transport of diplomatic personnel.