KABUL — As Afghanistan’s conflict intensifies, casualties among the country’s security forces are continuing to increase, a troubling sign while American and Taliban negotiators look to revive talks toward a peace deal likely to include a withdrawal of U.S. troops from the country.

Casualties among Afghan security forces increased by 5 percent from June through August this year compared with the same period last year, according to the U.S. Special Inspector General for Afghanistan Reconstruction’s quarterly report, which was released Thursday

Afghanistan’s military has struggled with high casualty rates for years. Last year, the Pentagon described casualties among Afghan security forces as “unsustainable.”

The government does not release the exact number, but in late 2018, President Ashraf Ghani said that more than 28,000 members of the Afghan security forces had been killed since 2015.

The persistent high casualties among Afghan security forces come as American and Taliban negotiators look to resuscitate peace talks that were upended by President Trump in September. A key element of any peace deal is expected to be a withdrawal of U.S. forces, a move that would significantly increase pressure on Afghanistan’s military. 

Earlier in October, the U.S. military mission in Afghanistan announced that it has already begun reducing personnel, bringing the total number of U.S. troops in the country to about 13,000. A spokesman for the command described the decrease as “an aggregate drop” and not part of a larger drawdown. 

Over the past year, the push for peace has brought with it a spike in violence in Afghanistan as both the U.S.-backed government and the Taliban have looked to gain negotiating leverage through battlefield gains

Those increased operations were also detailed in the watchdog report. The number of ground operations conducted by Afghan special operations forces is up. Those forces conducted 2,531 ground operations from January to September, outpacing the total number of operations carried out in 2018. And airstrikes have intensified: U.S. aircraft dropped more munitions on Afghanistan in September than in any other month since October 2010. 

The Afghan military also experienced an increase in casualties caused by “insider” attacks. From June through August this year, attacks on Afghan security forces carried out by their comrades resulted in 87 casualties. So far this year, 49 “insider” attacks have resulted in 167 casualties. 

 The United States has spent more than $70 billion training and equipping the Afghan military over the course of the country’s 18-year war, according to the government watchdog.