Kuwait’s 90-year-old ruling emir has cancelled a visit on Thursday with President Donald Trump at the White House after being admitted to a US hospital following an earlier health scare last month.

Sheikh Sabah Al Ahmad Al Sabah will undergo unspecified tests during his hospitalisation, the state-run Kuwait News Agency (Kuna) reported late Sunday, without elaborating.

It quoted Sheikh Ali Jarrah Al Sabah, the minister of the emir’s diwan council, as saying Sheikh Sabah would reschedule his visit with Trump.

“Sheikh Ali prayed to Allah the Almighty to bestow His Highness the Emir with good health,” Kuna said.

A White House statement said Trump was aware of the emir being hospitalised.

“The president wishes his friend, the Emir, a speedy recovery and looks forward to welcoming him back to Washington as soon as he is feeling better,” the statement said. “The Emir is a well-respected leader and has been a tremendous partner of the United States in tackling challenges in the region.”

On August 18, Kuwait acknowledged the emir suffered an unspecified medical “setback”.

That came after visiting Iranian Foreign Minister Mohammad Javad Zarif wrote on Twitter that he was “praying for emir’s speedy recovery”.

Sheikh Sabah has ruled Kuwait since January 2006. A longtime diplomat, he pushed for diplomacy to solve regional issues, such as the ongoing boycott of Qatar by four Arab nations, and hosted major donor conferences for war-torn nations like Iraq and Syria.