Afghan officials say coalition air support backed the guards during the battle, which lasted several hours; no security guards were killed
Officials in eastern Afghanistan say border guards backed by coalition air strikes have killed at least 26 militants near the Pakistani border.
No security guards were reported killed during the hours-long battle in Khost province.
On Tuesday this week, President Barack Obama is scheduled to announce his decision on U.S. strategy for Afghanistan. He is expected to send as many as 35,000 additional American troops to the region.
The Washington Post newspaper reported Sunday that the first group of additional troops will be as many as 9,000 Marines headed to the southern Taliban stronghold Helmand province.
Republican and Democratic lawmakers have said they will support a troop increase, but some have raised concerns over setting benchmarks for the Afghan government and laying out a U.S. exit strategy for the war.
In an televised interview Sunday on Fox News, Republican Senator John Kyl said he does not support an open discussion of a U.S. exit strategy because it will make the Afghan and Pakistani governments less confident that Washington is committed to eliminating the insurgent threat.
Democratic Senator Evan Bayh said he supports an exit strategy because it is one of the only ways to keep pressure on the two governments to stabilize their countries.
On Saturday, British Prime Minister Gordon Brown outlined a timetable for President Hamid Karzai to announce key security and political benchmarks.
Mr. Brown said he wants a "credible plan" from Mr. Karzai for training more Afghan troops by January 28 when Britain hosts an international conference on Afghanistan.
NATO allies, key world powers and regional neighbors are to attend the London conference.
Some information for this report provided by AP and Reuters.