Saudi Crown Prince Mohammed bin Salman and Qatar's Emir Sheikh Tamim exchanged a warm embrace on the tarmac at Al Ula airport after the Qatari delegation arrived for the 41st Gulf Co-operation Council summit on Tuesday.
Sheikh Tamim's attendance was another signal of moves towards reconciliation within the GCC, coming a day after Saudi Arabia reopened its borders and airspace to Qatar.
Qatar's emir is attending the GCC summit for the first time since 2017, when fellow bloc members Saudi Arabia, the UAE and Bahrain, along with Egypt, cut off ties over Doha's support for extremist groups.
Dr Anwar Gargash, the UAE Minister of State for Foreign Affairs, said the summit at Al Ula would be a "historic" meeting "through which we restore Gulf cohesion and are keen to ensure that the security, stability and prosperity of our countries and peoples are the first priority".
"We have more work [to do] and we are [going] in the right direction," he said on Twitter on Monday after the Saudi-Qatari decision was announced.
Bahrain's Crown Prince and Prime Minister Salman bin Hamad was the first regional leader to arrive for the summit. He was followed by the Omani delegation led by Deputy Prime Minister Fahad bin Mahmoud attending on behalf of Sultan Haitham.
Sheikh Mohammed bin Rashid, the UAE Vice President and Ruler of Dubai, arrived next with a delegation that included National Security Adviser Sheikh Tahnoun bin Zayed; Sheikh Mansour bin Zayed, the Deputy Prime Minister and Minister of Presidential Affairs; Minister of Cabinet Affairs Mohammad Al Gergawi; Minister of State for Foreign Affairs Dr Anwar Gargash; Ali Mohammed Al Shamsi, Deputy Secretary General at the Supreme National Security Council; and Sheikh Shakboot bin Nahyan, the UAE Ambassador to Saudi Arabia.
The UAE contingent was followed by the Kuwaiti delegation led by Emir Sheikh Nawaf, who said last week that he was optimistic about the meeting. The summit will bring GCC leaders together to strengthen their solidarity against the challenges in the region, he said.
All the delegations were received by Saudi Crown Prince Mohammed bin Salman.
US President Donald Trump's senior adviser, Jared Kushner, is also expected to attend the summit, according to a US official.