The latest military campaign in Afghanistan will most likely lead to “continued American casualties” as the U.S. takes a “new approach” in the troubled region, a top official at the Pentagon said Thursday.

Speaking at a press briefing, Marine Lt. Gen. Kenneth McKenzie, director of the Pentagon’s Joint Staff, told reporters that the Pentagon is sending more U.S. troops closer to the frontlines as they advise the Afghan troops in charge of airstrikes.

But he warned of the risk with this latest approach.

“Americans are at risk and unfortunately there’re probably going to be continued American casualties in this campaign,” McKenzie said.

In the growing effort to combat the Taliban, the U.S. will be deploying 1,000 more troops to Afghanistan by April, bringing the total number of troops to 15,000.

Just last week the U.S. Air Force deployed twelve A-10 Thunderbolt jets to provide air-support for both American and Afghan troops in the region. It also sent more drones and search and rescue helicopters.

The Trump administration has made serious gains against the Taliban, an effort that began after the 9/11 terror attacks.

Under Trump, boots on the ground have increased from around 8,400 to the anticipated 15,000 by spring.

The air operation has also been successful with more bombs being dropped in the region in 2017 than in 2012, according to the Air Force.

Trump has been vocal about increasing the number of troops on the ground as part of a commitment to defeating terrorism globally.

Despite sending more troops, U.S. involvement in Afghanistan is still much lower than when it hit its peak in 2010 with more than 100,000 troops in the region.

McKenzie said that deploying more troops under this “new approach” should have a different effect than prior campaigns.

“The difference this time,” he said, is that “it is the Afghans who are doing the fighting.”

Fox News’ Lucas Tomlinson contributed to this report.