As the civilian toll in Yemen’s war continues to rise, some lawmakers are beginning to question U.S. support for the Saudi-led coalition in what’s becoming increasingly known as the world’s largest humanitarian crisis.

A bipartisan bill introduced last month calls for Congress to investigate U.S. military involvement in Yemen, originally signed off by President Obama, who authorized unlimited military support for the Saudi air campaign in Yemen. The effort was subsequently re-approved by  President Donald Trump.

If passed, the bill would remove U.S. forces from involvement in the war in Yemen pending a vote by Congress to authorize U.S. military aid.

On Tuesday, Yemen’s special envoy to the U.N. blamed the country’s opposing leaders for the conflict, accusing them of putting personal greed and power above the needs of the suffering nation.

“They are not interested in finding solutions, as they will lose their power and control in a settlement,” Ismail Ould Cheikh Ahmed told the U.N. Security Council.

U.S. military presence in the Yemen conflict is limited to a handful of advisers whose primary aim is to advise on limiting civilian casualties, according to a Pentagon spokesman.

But the U.S. has played a far more active role in backing the Saudi-led coalition by selling arms to the Saudis and refueling Saudi aircrafts more than 9,000 times since 2015.

The bill, introduced by two Republican and two Democratic Congressmen, will require a vote in favor of further intelligence sharing with the Saudis and will allow Saudi aircrafts to be refueled by the U.S. military.

According to a 2016 State Department report on terrorism in Yemen, groups such as Al Qaeda and ISIS have taken advantage of the current security climate and tensions to rally support, a point cited in the bill, calling to suspend U.S.-Saudi cooperation pending Congress’ vote.

The bill, however, stops short of a complete suspension of counterterror operations.

The U.S. has operated a highly-publicized drone program in Yemen, launched after September 11, 2001, targeting dozens of Al Qaeda operatives, including noted propagandist Anwar Al Awlaki.

Humanitarian toll

Since the start of the Yemen conflict, more than 14,000 civilian casualties have been documented, and over three-quarters of a million cases of Cholera have been recorded. Saudi Arabia has also imposed a blockade on certain areas held by Houthi rebels, the Iran-backed fighters fighting Saudi forces, drawing ire from the World Food Program and condemnation from international rights groups.

Almost twenty million people are in need of humanitarian aid, leading three U.N. agencies to declaree the Yemen crisis the world’s largest humanitarian crisis.

“It’s beyond time for the country to stop conducting refueling for missions over Yemen. Congress and the American people know too little about the role we are playing in a war that is causing suffering for millions of people and is a genuine threat to our national security,” according to Rep. Ro Khanna, (D-California), one of the bill’s sponsors and a member of the House Armed Services Committee.