The GCC nations on Tuesday agreed to take a united stance against Iran after a successful meeting.
A statement after the 40th GCC summit at Riyadh's Al Daraya Palace stressed the need to increase military and security co-operation between the six member states to combat Iran’s malign threat.
“Members must complete all necessary measures to ensure the security and safety of the lands of the GCC states, their territorial waters and their economy,” they said.
The statement echoed sentiments expressed in Saudi King Salman's opening address, in which he urged members to secure themselves against missile attacks from hostile forces, but praised the GCC's ability to overcome crises in the region.
King Salman also warned against Iran.
“The Iranian regime has continued its aggressive policies in the region that undermine the stability of neighbouring countries,” he said.
The UAE, Saudi Arabia, Bahrain, Kuwait, Oman and Qatar come together every year to discuss trade and security co-operation.
Abdullatif Al Zayani, the GCC secretary general, said Tuesday's closed-door meeting was successful.
"We found it has been a fruitful and friendly meeting, expressing the depth of brotherhood ties that connect the GCC states and their people together, and their real desire to enhance their strength and unity between the GCC in all fields," Mr Al Zayani said.
"All of the Gulf States will unite against any aggressions and threats, to bridge the gap between some of the countries and to implement the agreements and initiatives between the countries."
The statement by the parties also called for legislation to be drawn up on regional economic integration by 2025, including financial and monetary unity.
“The challenges facing the region require a strength in co-operation between member states on the economic, cultural, security and political levels that will implement free trade negotiations,” it said.
This will benefit GCC citizens and enhance the council's international role, the statement said.
Saudi Foreign Minister Prince Faisal bin Farhan said on Tuesday evening that Iran was "a threat to all".
"We all understand it is necessary to deal with the threat using the right methods and we are able to stand against them," Prince Faisal said.
Iran must change its behaviour before going to the negotiating table to find a peaceful solution, he said.
“It is difficult to see that Iran can be a part of a security council in the region,” Prince Faisal said.
He said the Gulf leaders stressed the importance of solidarity in facing Tehran’s malicious actions.
“It is difficult to believe that they will be part of a peaceful solution,” Prince Faisal said.
Before the conference began in earnest on Tuesday, speculation was rife over whether the Qatari Emir, Sheikh Tamim, would attend. He did not attend.
Saudi Arabia, the UAE, Bahrain and Egypt cut ties with Doha in 2017 for interfering in their internal affairs and supporting extremist groups across the region.
Every crisis must come to a negotiated end that is “sincere and sustainable”, said the UAE’s Minister of State for Foreign Affairs, Dr Anwar Gargash.
Dr Gargash said the absence of Sheikh Tamim was caused by a miscalculation of the situation by his advisers.
“The roots of the crisis between Qatar and the four countries must be addressed in order to get to a solution,” he said on Twitter.
Mr Al Zayani thanked Kuwait for its mediating efforts and said talks were continuing with hopes of ending the dispute.
Tuesday's meeting took place after King Salman personally welcomed the heads of delegations from the GCC, including Sheikh Mohammed bin Rashid, Vice President and Ruler of Dubai.
Also present were Kuwaiti Emir Sheikh Sabah, Bahrain's King Hamad and Qatari Prime Minister Sheikh Abdullaha bin Nasser, and Oman's Deputy Prime Minister for the Council of Ministers, Fahd bin Mahmoud.
The next meeting will take place in Bahrain.
Mr Al Zayani announced that his tenure as secretary general would come to an end in April.
He confirmed that former Kuwaiti finance minister Nayef Al Hajraf would be the council’s next secretary general.
Mr Al Hajraf will become the second Kuwaiti to become the GCC’s secretary general since it was established in 1981.
