DHAHRAN, Saudi Arabia, April 15 (Xinhua) -- The 29th Arab League (AL) Summit kicked off in Saudi Arabia's eastern city of Dhahran on Sunday, with leaders from 22 member states attending it.

The summit will focus on Palestinian-Israeli conflicts, the Syrian crisis especially after an alleged chemical attack and the U.S.-led airstrikes, Yemen's civil war, as well as fighting against terrorism.

UN Secretary General Antonio Guterres, AL Secretary General Ahmed Aboul-Gheit and Chairman of the African Union Commission Moussa Faki and High Representative of the European Union for Foreign Affairs and Security Policy Federica Mogherini are also participating in the one-day summit.

Saudi King Salman bin Abdulaziz Al Saud referred to the Palestinian issue as the top agenda of the Arab meeting.

"The Palestinian case is our priority and will remain so until all the Palestinians gain their rights," he said, stressing that East Jerusalem is the capital of Palestine.

The king also denounced Iran's interference in other states' internal affairs by committing "terror acts," calling for the unity of the Arab world against it.

AL Secretary General Ahmed Aboul-Gheit noted that the crises gripping the Middle East will further deteriorate and weaken the entire region if not harnessed.

He believed there has been a huge setback in the process of solving the Palestinian-Israeli conflict after U.S. President Donald Trump's announcement.

On Dec. 6, 2017, Trump announced his official recognition of Jerusalem as Israel's capital and instructed the relocation of the U.S. embassy from Tel Aviv to the disputed holy city, which promptly triggered fury and condemnation throughout the Arab world.

The situation has become even worse since the beginning of the six-week "Great March of Return" rally by Palestinians on March 30, where 32 Palestinians have been killed and more than 3,000 others injured in clashes with Israeli soldiers on the Gaza border areas.

"So it is important to support Palestinians and (Palestinian President) Abbas," Aboul-Gheit said.

The AL chief also slammed Iran for its support for the Shiite Houthi rebels in Yemen, saying the Arab states should unite with Saudi Arabia against Iran.