Foreign Minister AK Abdul Momen has left for the United Arab Emirates (UAE) to join the ongoing three-day period of mourning following the death of Sheikh Khalifa bin Zayed Al Nahyan, president of the UAE and ruler of Abu Dhabi.  Momen left Dhaka on Saturday evening where he will represent the Bangladesh government, said a foreign ministry official. The foreign minister will return home Monday, he added.  Read: UAE's long-ailing leader Sheikh Khalifa bin Zayed dies at 73 In separate messages, President Abdul Hamid and Prime Minister Sheikh Hasina expressed their condolences on the passing of Sheikh Khalifa.  The president and prime minister recalled the late UAE president's visionary leadership and his friendship with Bangladesh and prayed for the salvation of the departed soul. Oman's sultan was among the first leaders to visit the UAE's new President Sheikh Mohamed bin Zayed Al Nahyan Saturday night, reports AP.  Others are expected in the coming days, including French President Emmanuel Macron Sunday.The UAE as a whole is observing a three-day period of mourning, which will see businesses shut across the country and performances halted in Sheikh Khalifa's honour.  Read:No need to import wheat before August, says food secretary Electronic billboards all showed the late Sheikh's image in Dubai Friday night as flags flew at half-staff.  A wider mourning period of 40 days will go on beyond that. Rulers in the UAE Saturday unanimously appointed Abu Dhabi's Sheikh Mohammed as the country's president, signalling both unity and stability in this key energy-rich country that hosts Western militaries.