Four coalition soldiers have been killed in three separate attacks in Afghanistan, Nato officials say.
It said that two American troops were killed in a suicide attack on a military convoy in the south of the country on Friday.
Another American soldier died as a result of a grenade attack in the east of the country.
Nato said the fourth serviceman - who was British - died in a bomb attack in southern Afghanistan on Thursday.
The latest deaths come as US President Barack Obama summoned his top commander in Afghanistan for a meeting aboard Air Force One as part of his review of the war strategy.
Gen Stanley McChrystal met Mr Obama as the president returned to Washington from Copenhagen, where he was supporting Chicago's bid to host the 2016 Olympic Games.
Gen McChrystal had been in London, where he said in a speech on Thursday that insurgents were gaining strength in Afghanistan and more troops were needed to "buy time" for the Afghan military and police forces to prepare to take control of the country in 2013.
This year has been the deadliest yet for international troops in Afghanistan since the overthrow of the Taliban government in 2001.
Figures compiled by the Associated Press news agency show that the number of coalition troop deaths for September stood at 65, compared with 73 in August, 75 in July and 34 in June.
At the same time, civilian deaths rose from 169 in August to 202 in September.