UAE's leader Sheikh Khalifa bin Zayed has died

The UAE’s Ministry of Presidential Affairs announces a 40-day period of mourning and a three-day suspension of work in all ministries and the private sector.

ABU DHABI - The United Arab Emirates' long-ailing ruler, Sheikh Khalifa bin Zayed Al Nahyan, died Friday, the government's state-run news agency announced in a brief statement. He was 73.

The UAE’s Ministry of Presidential Affairs announced a 40-day period of mourning and a three-day suspension of work in all ministries and the private sector beginning Friday, including flags to be flown at half-staff.

He had long ceased having involvement in day-to-day affairs, with his brother, Abu Dhabi's Crown Prince Sheikh Mohammed bin Zayed, seen as the de-factor ruler. There was no immediate announcement about the successor.

"The UAE lost its righteous son, the leader of the “empowerment stage” and the trustee of its blessed journey.. His stances, achievements, wisdom, giving and initiatives in every corner of the country.. Khalifa bin Zayed, my brother, my mentor and my teacher, may God have mercy on you with his vast mercy and enter you into his good pleasure and paradise," tweeted Sheikh Mohammed bin Zayed.