The United Nations has once more accused Houthi militias of hindering the delivery of humanitarian aid to areas they control in Yemen.

Ursula Mueller, Assistant Secretary-General for Humanitarian Affairs and Deputy Emergency Relief Coordinator, told the Security Council that despite recent limited improvements, Houthis continue to enforce a growing number of restrictive regulations on humanitarian action.

The insurgents “are still blocking or delaying half of all NGO projects in areas under their control,” Mueller said.

The UN official explained that although UN partners are still able to deliver aid, they need to go through "constant engagement at all levels," often resulting in unacceptable delays for people who need help.

Mueller said Houthis continue their campaign to coerce UN humanitarian partners into working under conditions that would contradict humanitarian principles and almost certainly result in loss of funding and closure of programs.

The UN accusations angered Houthi leaders, who claimed that the UN and their partners should be blamed for the obstruction of humanitarian aid.

Member of the Yemeni Supreme Political Council Mohammad Ali al-Houthi wrote on his Twitter account Saturday that international organizations are manipulating donor funds and not allocating them to serve citizens.

Another Houthi leader, Abdel Mohsen Taous, claimed the militia group possesses documents that prove the UN accusations were false, saying the Houthis would be compelled to reveal them.

Some 250 humanitarian partners are working with the UN to assist more than 13 million people across the country.

The Yemeni government has repeatedly called on the international community and humanitarian relief groups to weigh in and place pressure on Houthis so that they stop hindering the delivery of aid in Yemen.