The United States offered condolences after four unarmed French troops were killed by an Afghan soldier Friday, Jan 20, and said it was up to France whether to bring its forces home from Afghanistan early, AFP reported.

"We mourn for their losses today, but those are decisions that only the French government and the French people can make," Navy Captain John Kirby, a Pentagon spokesman, said of French President Nicolas Sarkozy's warning of a possible early withdrawal.

"Their contributions are theirs to determine and theirs to amend as they see fit," Kirby said, calling the French "great allies and great friends."

Reacting to the killing, French President Nicolas Sarkozy said that France is suspending its training programs for Afghan troops.

Sarkozy said it's "unacceptable" that Afghan troops fire at French soldiers. He said French Foreign Minister Alain Juppe is heading to Afghanistan.