ABC News' Mike Boettcher reports:
BAGRAM AIR FIELD, Afghanistan - U.S. Army Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, was at Bagram Air Field tonight to meet with top U.S. and Afghan officials in Kabul in an attempt to stop the increasing number of attacks on U.S. forces by Afghan soldiers and police in what are being called "green on blue" or "insider" attacks.
In the last 12 days, 10 American soldiers have been killed in insider attacks in Afghanistan.
Many of the attacks are being blamed on renegade Afghan soldiers angry at their U.S. counterparts.
The Taliban, however, has claimed credit for the attacks and U.S. commanders are investigating whether they are Taliban-inspired.
Steps have been taken to stop the shootings. Afghan commanders are now closely scrutinizing their recruits and American soldiers have been ordered to carry loaded weapons wherever they go - even on a large, secure base like Bagram.
To me, there is now a slightly different feel on this base that I have visited dozens of times.
One soldier told me that he was more vigilant, but not paranoid, for the time being.
At the mess hall tonight, Americans sat at their tables, weapons loaded, as two Afghan soldiers passed with their trays. The Afghans carried no weapons at all.
It's a sign that while the Americans aren't taking any chances, the Afghan soldiers want to make sure they don't provoke.
Dempsey said the Afghan war effort "remains on track."
President Obama also spoke of the attacks today, saying that he planned to speak with President Hamid Karzai to ensure that "we are on top of this."