The United States will halt humanitarian assistance to Houthi-controlled areas in Yemen, where a majority of the country’s population lives, if the rebels refuse to remove obstacles to aid distribution. The announcement, made Feb. 25 by the US Agency for International Development (USAID), came amid new evidence that humanitarian assistance is not reaching its intended targets and growing security concerns by the agency and its partners.

“This decision is a last resort that follows more than a year of advocacy and diplomatic engagement calling on the Houthis in Yemen to respect humanitarian principles and allow the provision of needs-based humanitarian assistance without interference,” a USAID spokesperson told Al-Monitor. If the Houthi rebels refuse to cooperate, the aid suspension will go into effect in late March.

USAID provides supplies to the people of Yemen along with other support through partners on the ground and international non-governmental organizations. The agency informed its partners in February about its decision to potentially halt assistance.

The rebels have granted aid workers access to areas under their control, but they have also made excessive demands, including a 2% slice of the UN aid budget designated for Yemeni assistance, a condition the United Nations and its donors have rejected.