Confirming the order from the de facto authorities, who control the capital Sana’a along with many other areas of the war-torn country, UN Spokesperson Stéphane Dujarric told reporters that the demand ran counter to the legal conditions under which the UN and non-governmental organizations (NGOs) operate.

Yemen descended into all out conflict in 2015, with Houthi rebels battling internationally recognized Government forces allied with a Saudi-led coalition.

A fragile cessation of hostilities broadly holds within Yemen’s borders, but Houthi attacks on Red Sea shipping in solidarity with Palestinian militants fighting in Gaza has seen dozens of airstrikes in recent days by the United States and United Kingdom in retaliation.

Cargo vessels have been forced to divert from the Red Sea, threatening global trade and international economic recovery.

No legal basis

Confirming the letter demanding the exit of Sana’a-based staff, Dujarric stressed that “any request or requirement for UN staff to leave based solely on the nationality of that staff is inconsistent with the legal framework applicable to the UN."

He noted that it also “impedes our ability to deliver on the mandate to support all of the people in Yemen, and we call on all the authorities in Yemen, to ensure that our staff can continue to perform their functions on behalf of the UN”.

The letter from the Houthi’s de facto foreign ministry in the capital was reportedly sent to the UN’s acting Humanitarian Coordinator, Peter Dawkins, himself a British national.

It reportedly also ordered foreign organizations not to hire US and British personnel going forward.

Dujarric emphasized that UN staff “serve impartially and serve the flag of the UN – and none other”.