Bahraini Prime Minister Khalifa Bin Salman Al Khalifa died on Wednesday in a hospital in the US, the country's royal court said. He was 84.

"The Royal Court mourns His Royal Highness… who passed away this morning at Mayo Clinic Hospital in the United States of America," the Bahrain News Agency said on Wednesday, without elaborating.

The Gulf kingdom's King Sheikh Hamad bin Isa Al Khalifa announced official mourning for a week during which flags will be flown at half-mast, the agency said.

The burial ceremony will take place upon the repatriation of his body and the funeral will be limited to a specific number of relatives, it said.

Khalifa Bin Salman Al Khalifa was one of the world's longest-serving Prime Ministers who led his island nation's government for decades and survived the 2011 Arab Spring protests that demanded his removal over corruption allegations..