Iran’s top diplomat to Houthi-controlled Yemen has died of Covid-19 after a hastily arranged flight out of the country over the weekend, Iranian officials said.

Hassan Irloo, a member of the Islamic Revolutionary Guard Corps, was smuggled into Yemen and named Iran’s ambassador in November 2020 to parts of the country controlled by the Houthis. His installment was condemned in Washington and Riyadh and seen as a sign of an emboldened Iran, as the Houthis made gains in Yemen’s civil war.

As recently as Sunday, Iranian officials said Mr. Irloo’s medical condition was stable. In announcing his death Tuesday, Iran’s foreign ministry spokesman blamed unnamed countries for delaying Mr. Irloo’s transportation home.

“He was executing his mission and because of late cooperation of some countries returned to the country in unwell conditions,” said Saeed Khatibzadeh, a spokesman with Iran’s foreign ministry.