Gulf leaders pledged at the annual GCC summit to play a constructive role in strengthening security and stability in the region against external threats and regional conflicts.
The meeting is held yearly between leaders from Bahrain, Kuwait, Oman, Saudi Arabia, the UAE and Qatar, for discussion on security, economy and political integration and co-operation.
Leaders put "collective security, regional conflicts and development" at the top of the agenda.
They agreed upon the importance of the GCC’s common economic, defence and security integration to enhance stability among member states.
“The leaders stressed the vital need for common foreign policies of member states to build a shared foreign policy that serves the aspirations and ambitions of their people and preserve their interests and gains,” stated the Riyadh Declaration issued at the end of the summit late on Tuesday in Riyadh.
The summit comes as world leaders convene to revive Iran's tattered 2015 nuclear deal in Vienna.
The officials also discussed continuing wars in Yemen and Syria and Lebanon's economic and political problems.
Who was there?
Oman's Deputy Prime Minister, Sayyid Fahad bin Mahmoud Al Said, was the first to arrive with his country's delegation and he held talks with Saudi Arabia’s Crown Prince Mohammed bin Salman.
Sheikh Mohammed bin Rashid, Vice President and Ruler of Dubai, led the UAE's delegation and was welcomed to the summit by the crown prince.
Shortly before he arrived in Riyadh, Sheikh Mohammed said: “We need a strong start for the fifth decade of the Gulf Co-operation Council. We are looking forward to economic integration. We are looking for real and deep co-operation.”
Sheikh Tamim bin Hamad Al Thani, the emir of Qatar, also attended the summit, the first time Gulf leaders had assembled since signing the historic AlUla agreement in January to end a rift with Qatar that lasted three and a half years.
Kuwait's Crown Prince Sheikh Meshaal Al Ahmed Al Sabah headed his country's delegation. Bahrain's delegation was led by King Hamad.
The summit was also attended by Egyptian Foreign Minister Sameh Shoukry.
The GCC secretary general Dr Nayef Al Hajraf presided over the meeting.
Dangers posed by Iran
He called for an "effective and serious" approach to the nuclear deal.
"It is important to have an effective and serious approach to Iran's nuclear and ballistic programme," the crown prince said.
Saudi Arabia's Foreign Minister Prince Faisal bin Farhan said after the summit that the evolution of the Vienna negotiations "is worrying and does not create optimism".
He said a Saudi Arabian presence at the talks “would allow us to be close to solutions since we are one of the countries most threatened”.
“Iran maintains an intransigent position … and that is certainly worrying,” he said.
Closing remarks read by Dr Al Hajraf stressed the importance of joint efforts by Gulf states to avoid regional and international conflict.
"Member states of the GCC consider that any attack on any of them is an attack on them all and any danger that threatens one of them is threatening them all," he said.
King Hamad hailed the Saudi Arabian crown prince's recent tour of the Gulf, which sought to enhance co-ordination between GCC states and strengthen the work of the regional body.
“We laud the results of the Gulf visit by Saudi Crown Prince Mohammed bin Salman which has positively paved the way for this summit,” he said.
He commended the crown prince's aim to “bring different points of views closer and overcome challenges” during his trip, which included Bahrain, Oman, the UAE, Qatar and Kuwait.
The non-GCC member in attendance was Egypt, represented by Mr Shoukry.
He stressed the need to bring Egypt and the GCC states closer together.
“Facing and overcoming challenges and preserving Arab security will only be achieved through solidarity, co-operation and closer ties between us, both politically and economically," he said during a press conference with his Saudi counterpart Prince Faisal and Dr Al Hajraf.