July is deadliest month of Afghanistan war for US
American forces have experienced their deadliest month in the nine-year-old Afghan war, with 63 US service members killed in July.
June's record of 60 was surpassed after it was confirmed three soldiers killed in the south of the country on Thursday were Americans.
Meanwhile, hundreds of UK and Afghan troops launched a major offensive against the Taliban in Helmand.
Casualties have risen as the war escalates against a resurgent Taliban.
US President Barack Obama ordered 30,000 reinforcements to Afghanistan last December.
On yesterday morning, British and Afghan troops pushed into the Nad Ali district of Helmand, aiming to flush the Taliban from one of its strongholds in the province.
Operation Tor Shezada, which means black prince, is said to be UK forces' largest operation since Moshtarak in February 2010.
Nad Ali is one of the areas that UK forces were unable to clear during Moshtarak.
June this year was the deadliest month since the US-led invasion of 2001 for international forces in Afghanistan, with 102 service members killed, according to the independent iCasualties website.