Mashable: He was 86 years old.

Kuwait's Emir, Sheikh Nawaf al-Ahmad al-Jaber al-Sabah, has passed away at the age of 86, as announced by Sheikh Mohammed Abdullah al-Sabah, the minister of his emiri court. The cause of death has not been disclosed.

Sheikh Meshal al-Ahmad al-Jaber, the deputy ruler and half-brother at 83, is expected to succeed him, though there has been no official confirmation. Sheikh Nawaf assumed the role of emir in September 2020 after the death of his half-brother, Sheikh Sabah al-Ahmad al-Jaber al-Sabah.

His Highness the Amir of Kuwait Sheikh Nawaf Al-Ahmad Al-Jaber Al-Sabah has passed away, the Amiri Diwan announced on Saturday. pic.twitter.com/9y4ap1LLu2

— KUWAIT TIMES (@kuwaittimesnews) December 16, 2023
#BREAKING: #Kuwait government declares three-day holiday, 40-day mourning period following Emir Nawaf's passing pic.twitter.com/YequXd6xTU

— Saudi Gazette (@Saudi_Gazette) December 16, 2023
In response to the news, the President of the UAE, Sheikh Mohamed bin Zayed Al Nahyan, declared a three-day national mourning period and ordered flags to be flown at half-mast.

The #UAE President, @MohamedBinZayed on Saturday declared a 3-day national mourning period over the death of Kuwait's Emir Sheikh Nawaf Al Ahmad Al Sabah.

Details: https://t.co/9ObCGqpDb8#Kuwait #SheikhNawaf pic.twitter.com/q0MdU9PA2F

— Khaleej Times (@khaleejtimes) December 16, 2023
Condolences poured in from leaders worldwide, including Sheikh Mohammed bin Rashid Al Maktoum and Saudi Arabia's King Salman and Crown Prince Mohammed bin Salman. Sheikh Nawaf, known for his six-decade service to Kuwait, had a reputation for modesty and reconciliation, earning him the nickname "the emir of pardons."

رحم الله الشيخ نواف الأحمد الجابر الصباح وتغمده بواسع رحمته ومغفرته، وخالص العزاء وعميق المواساة إلى آل الصباح الكرام والشعب الكويتي الشقيق في هذا المصاب الجلل. لقد كان الراحل الكبير قائدًا حكيمًا قام بدور كبير في تعزيز العلاقات الإماراتية-الكويتية ودعم العمل الخليجي المشترك.

— محمد بن زايد (@MohamedBinZayed) December 16, 2023
I extend my sincere condolences to the Kuwaiti government and people over the passing of Sheikh Nawaf Al-Ahmad Al-Jaber Al-Sabah. Our heartfelt sympathies are with his family and the entire nation, and we pray that God rests his soul in eternal peace.

— محمد بن زايد (@MohamedBinZayed) December 16, 2023
#BREAKING: #SaudiArabia’s King Salman and Crown Prince Mohammed bin Salman extend their condolences to #Kuwait's Al-Sabah family and its citizens on the passing of Emir Sheikh Nawaf Al-Ahmad https://t.co/k3bvV04FG2 pic.twitter.com/NmG9NUK41N

— Saudi Gazette (@Saudi_Gazette) December 16, 2023
The Prime Minister @RishiSunak has offered his deepest condolences to the Kuwaiti people and the Al Sabah family on the death of His Highness the Amir of Kuwait, Sheikh Nawaf Al Ahmad Al Jaber Al Sabah. pic.twitter.com/VxnbCCgU8a

— UK Prime Minister (@10DowningStreet) December 16, 2023
Facing economic challenges during his tenure, particularly a drop in oil prices, Sheikh Nawaf navigated the crisis and addressed the impact of the COVID-19 pandemic on Kuwait's economy. His likely successor, Sheikh Meshal, is described as both an insider and an outsider, having played a role in governmental decisions.

Deeply saddened by the news that Amir of Kuwait, His Highness Sheikh Nawaf Al Ahmad Al Jaber Al Sabah has passed away. Pakistan stands in solidarity with the Kuwaiti Royal Family and the people of Kuwait at this moment of grief. May Allah SWT bless the departed soul with the…

— Anwaar ul Haq Kakar (@anwaar_kakar) December 16, 2023
Deeply saddened by the passing of HH Sheikh Nawaf Al Ahmed Al Sabah, the Amir of Kuwait. His legacy of leadership and service will be remembered by the nation and beyond. My heartfelt condolences to the people of Kuwait during this period of mourning. https://t.co/eJ19GXt9qV

— Deemah AlYahya (@Dalyahya) December 16, 2023
Sheikh Nawaf's health had been a concern since late November when he was hospitalized for an unspecified illness. The emir had previously handed over power during medical checks and had traveled to the United States for health reasons in March 2021.

#BREAKING: #Kuwait Cabinet names Sheikh Mishal Al-Ahmad Al-Jaber Al-Sabah Emir of Kuwait. pic.twitter.com/wochcxX1B9

— Saudi Gazette (@Saudi_Gazette) December 16, 2023
Born in 1937, Sheikh Nawaf began his political career at 25 as the governor of Hawalli province and served in various high-profile positions, contributing to Kuwait's political landscape.