A group of US senators on Wednesday said they feared US efforts to draw down military forces in Afghanistan had contributed to "insider attacks" by Afghans on NATO troops and called for a suspension of troop withdrawals, DPA reported.
"In light of the tragic recent attacks on US and NATO forces in Afghanistan, we understand and respect the rationale for scaling back combined operations between coalition and Afghan troops," wrote John McCain, Joe Lieberman and Lindsey Graham in a joint statement.
"However, we also believe this decision raises questions about the broader strategy that the Obama administration has been pursuing in this conflict, especially with respect to its timetable for drawing down our military forces in Afghanistan."
They said conditions in Afghanistan warranted "an immediate suspension" of US troop withdrawals to allow commanders to evaluate how to proceed. A rush to handover security to Afghan forces had contributed to so-called "green on blue" attacks on NATO troops, they alleged.
"We cannot afford to rush to failure in Afghanistan," they wrote.
The White House however stressed it was not going to reevaluate its plans.
"The president believes that after a decade of war, we can and should pursue a strategy that transitions security authority over to Afghan forces and allows us to end the war in Afghanistan and bring home our men and women in uniform. That process is under way," spokesman Jay Carney said.
President Barack Obama held a video conference with Afghan President Hamid Karzai Wednesday and discussed efforts to prevent insider attacks along with other issues.
NATO insisted Tuesday that its strategy for Afghanistan was still on track, after limiting operations with Afghan security forces to reduce the risk of attacks from local troops.
The decision came after four Americans and two British were killed by Afghan police in the south of the country over the weekend - part of a surge in so-called "green-on-blue" attacks this year.
More than 50 NATO-led troops have been killed this year by Afghan police and soldiers.