Relief organizations working in Yemen are urging Congress to speak out against the Donald Trump administration’s plan to designate the Houthis as a terrorist organization, warning that such a move could have drastic humanitarian consequences in a country on the brink of famine. 

“A formal US terrorist designation would exacerbate humanitarian needs, further devastate Yemen’s economy, and hamstring the ability of humanitarian agencies to respond,” read the letter sent Thursday to congressional leaders.

A coalition of 29 relief groups including the Norwegian Refugee Council, Oxfam America and the International Rescue Committee, called on US lawmakers to use their leverage to “help prevent millions of Yemenis from facing another year of violence, starvation, and disease.”

The State Department is considering designating the Houthis as a “foreign terrorist organization” in what observers say is a continuation of the Trump administration’s maximum pressure campaign on the Houthis' regional backer, Iran. The label would criminalize material support for the rebel group, which is embroiled in a years-long war with Saudi-backed pro-government forces.