Leaders of Islamic nations affirmed their support for the Palestinian cause ahead of a US-led peace plan suspected to favour Israel and rallied around Saudi Arabia over tensions with Iran.
Gulf and Arab leaders at the Organisation of Islamic Co-operation (OIC) talks in Makkah on Friday, the third summit hosted by Saudi Arabia over two days, denounced the controversial US moves to transfer its embassy to Jerusalem and recognise Israel's sovereignty over the Golan Heights.
A communique issued after the meeting, which was not attended by Iran and Turkey's leaders, also urged OIC members to boycott countries that have opened diplomatic missions in the city.
The statement comes as US President Donald Trump's son-in-law Jared Kushner prepares to roll out economic aspects of his long-awaited Middle East peace plan at a conference in Bahrain later this month.
The plan, dubbed by Mr Trump as the "deal of the century", has already been rejected by the Palestinians, who say the US president's policies have shown him to be biased in favour of Israel, such as his decision to recognise Jerusalem as the capital of Israel.
The 57-member OIC also backed Saudi Arabia over escalating tensions with Iran, as King Salman warned that "terrorist" attacks in the Gulf region could imperil global energy supplies,
Sabotage attacks damaged four vessels, two of them Saudi oil tankers, off the UAE coast in early May and were followed days later by Yemeni rebel drone attacks that shut down a key Saudi oil pipeline.
"We confirm that terrorist actions not only target the kingdom and the Gulf region, but also target the safety of navigation and world oil supplies," the Saudi king told OIC member states.
The US Secretary of State Mike Pompeo and White House security adviser John Bolton have said Iran was behind the attacks, a charge Tehran denies.
In a tweet just before the start of the OIC summit, King Salman vowed to confront "aggressive threats and subversive activities".
"Undermining the security of the kingdom effectively undermines the security of the Arab and Islamic world," said OIC Secretary General Yousef bin Ahmed Al Othaimeen, voicing solidarity that was shared by other members.
The summit marked Saudi Arabia's assumption of the rotating OIC presidency from Turkey in the year when the organisation marks the 50th anniversary of its founding.
The OIC communique also stressed the need for member states to close ranks against terrorist organisations and enact laws and controls to counter terrorism. It also rejected attempts to link terrorism to nationality, civilisation or religion, and the providing of support to any groups or organisations that incite violence, extremism and terrorism.
The OIC expressed concern over growing Islamophobia around the world, describing it as "a contemporary form of racism and religious discrimination" whose spread was evident "by the increase in incidents of religious intolerance, negative stereotyping, and hatred and violence against Muslims".
It called on the United Nations to observe March 15 as the International Day Against Islamophobia.