Yemen’s Houthi authorities have ordered US and British staff of the United Nations and Sanaa-based humanitarian organisations to leave the country within a month, Reuters reports quoting a document and a Houthi official as saying.

“The ministry … would like to stress that you must inform officials and workers with US and British citizenships to prepare to leave the country within 30 days,” said a letter sent by the Houthi foreign ministry to the UN’s acting humanitarian coordinator in Yemen, Peter Hawkins.

The letter also ordered foreign organisations to not hire American and British citizens for Yemen’s operations.

Houthi top negotiator Mohammed Abdulsalam confirmed the letter’s authenticity to Reuters.