He added that the wounded troops are “in good spirits.”
The troops came under fire during what Nicholson called “clearing operations” as U.S. and Afghan troops pushed into southern Nangahar following a series of airstrikes.
In January, President Obama gave additional authorities to ground commanders in Afghanistan, allowing them to target the growing cell of Islamic State fighters in the country’s east. At the time, their presence was estimated to be around 3,000 fighters, though Nicholson says he believes that number has been cut in half in the past six months following Afghan-led offensive operations supported by U.S. troops and airstrikes.
“It’s a very dynamic battlefield down there … but we think we’ve reduced their numbers very significantly,” Nicholson said.
Nicholson added that a majority of the Islamic State fighters in Afghanistan, roughly 70 percent, are former Pakistani Taliban members who had joined the Islamic State earlier this year.
Despite shrinking numbers and a loss of territory, the Islamic State carried out a suicide bombing in Kabul over the weekend that killed more than 80.
The joint U.S.-Afghan offensive operations against the Islamic State are just one part of a broader 2016 battle plan in Afghanistan, Nicholson said, one that involves widespread offensive operations against the Taliban, the Islamic State and other terrorist groups in the country.
Because of the uptick in operations, Afghan casualties are trending 20 percent higher than they were in 2015, Nicholson said. Additionally, U.S. forces have taken advantage of new authorities granted by Obama that allow for more leeway when it comes to advising and clearing airstrikes to better assist Afghan forces on the offensive. Nicholson said that since Obama approved the new authorities in June, the U.S. coalition in Afghanistan has conducted 40 airstrikes in support of their Afghan allies.