The United States will send more than 100 military advisers to help the Yazidis in Iraq, according to CNN.

"People are looking at ways to do something more than just drop water and supplies," a senior U.S. official told The Wall Street Journal. "You can only do that for so long."

President Barack Obama initially sent some 300 advisers to the region, both to guide Iraq's forces as well as protect the embassy in Baghdad. 

The military advisers would look at humanitarian relief options for the group, according to the report. This would be the first time, if approved, that U.S. forces would be in direct conflict with the Islamic State. 

The United Nations estimates that as many as 30,000 Yazidis may still be trapped in northern Iraq, fleeing the advance of the aggressive and violent Islamic State. On Sunday, there were reports that as many as 500 Yazidis had been slaughtered by Islamic State forces including women and children.

In the meantime, thousands of the Christian minority refugees remain stranded atop the Sinjar mountains without food, water, or shelter. Hundreds have reportedly died. The Defense Department has already been stepping up its efforts in recent weeks. Last week, the department outlined its humanitarian aid:

To date, in coordination with the government of Iraq, U.S. military aircraft have delivered 36,224 meals and 6,822 gallons of fresh drinking water, providing much-needed aid to Iraqis who urgently require emergency assistance.

It hasn't been easy. Earlier on Tuesday, a helicopter delivering aid and helping to shuttle Yazidis away from harm's way crashed, killing a pilot and injuring lawmakers and journalists.

Senator Tim Kaine (D-Va) voiced concern over the administration's efforts in Iraq, citing the need for Congress' involvement with any additional action.

"I support providing humanitarian relief to Iraqi civilians and measures to protect American personnel, but I am concerned about the timeline and scope of our renewed military efforts in Iraq," he said on Tuesday. "No one doubts the barbarity of IS and threat it poses to our partners and I will always support the President if he takes action to protect American servicemembers and diplomats.  But the mission and objectives of any military action must be made clear to Congress, the American people, and our men and women in uniform."