The United States, Britain and France may be complicit in war crimes in Yemen by arming and providing intelligence and logistics support to a Saudi-led coalition that starves civilians as a war tactic, the United Nations said on Tuesday.

Saudi Arabia is struggling to hold together a military coalition fighting Iran-aligned Houthis in Yemen after local allies turned on each other in a power struggle that has strained Riyadh's alliance with its main regional partner, the United Arab Emirates.

The United Arab Emirates carried out air strikes against government forces in South Yemen on Thursday in support of southern separatists who have deployed reinforcements to take back control of the port of Aden from their supposed allies in the Saudi-led coalition.

Yemeni President Abd-Rabbu Mansour Hadi said on Thursday that government forces had withdrawn from Aden to prevent the city from being destroyed, according to state news agency SABA .

Saudi Arabia and the United Arab Emirates (UAE) have looked inseparable on the world stage, working together to project power in the Middle East and beyond, and courting U.S. President Donald Trump to counter common foe Iran.

The president of Yemen's Southern Transitional Council (STC) headed with a delegation to the Saudi city of Jeddah on Tuesday after accepting the kingdom's invitation to a summit on the crisis in the Yemeni port city of Aden, the council said.

The refusal of Yemeni southern separatists to hand back control of Aden port has delayed a summit in Saudi Arabia that is due to discuss reshuffling Yemen's ousted government to include the separatists and end the stand-off, three Yemeni sources said.

Yemen's southern separatists said on Thursday they were ready to attend a summit in Saudi Arabia to resolve a standoff in Aden after they seized the southern port, seat of Yemen's Saudi-backed government.

A joint Saudi-Emirati military delegation travelled to Aden on Thursday to discuss demands for a pullout of UAE-backed southern separatists from positions they captured in Yemen's interim capital, government and separatist sources said.

Yemen's southern separatists vowed on Wednesday to keep control over Aden, warning the only way out of the impasse that has fractured a Saudi-led military alliance was for Islamists and northerners to be removed from positions of power in the south.

A report issued by World Resources Institute said that nearly a quarter of the world's population living in 17 countries, including India, Saudi Arabia, Pakistan and Libya, are facing extremely high water stress, close to "day zero".

The United Arab Emirates on Monday downplayed a rift with ally Saudi Arabia over Yemen after separatists it backs took control of Aden that was the base of the Saudi-backed government.

People connected to the government of Saudi Arabia have run a network of fake accounts and pages on Facebook Inc to promote state propaganda and attack regional rivals, the social media giant said on Thursday.

Iran is prepared for dialogue if Saudi Arabia is also ready, Iranian Foreign Minister Mohammad Javad Zarif was quoted as saying on Wednesday.

Iran was to revive maritime security talks on Tuesday with traditional foe the United Arab Emirates (UAE) in an apparent bid to calm tensions in the Gulf, although a Gulf official described the discussions as routine and technical.

A United Arab Emirates' military drawdown in Yemen is building momentum for a nationwide truce this year, bolstering efforts by the Saudi-led coalition it is part of to end a war that has tarnished the image of U.S.-allied Gulf states.

The Secretary-General of the National Adala (Justice) movement, extremist Salafist Mohieddin Khan didn’t deny the content of “Al-Jazeera” tape and didn’t even show interest to justify anything, whether in terms of what mentioned in “What is Hidden is Worse” or in terms of what his companions in the terrorist cells said inside the chambers of the National Security Agency. He only acquitted himself of being the one who sold the tape. He says in a video he recorded in response on what he described as “Fabrications of Bahrain Television report”: “It is very big and not good to accuse me of this case.”

U.S. President Donald Trump met on Thursday with the chief executives of major American airlines to discuss their accusations that subsidies by Qatar and United Arab Emirates are costing jobs in the United States.

United Nations aid chief Mark Lowcock called out Saudi Arabia and the United Arab Emirates on Thursday for only paying a "modest proportion" of the hundreds of millions of dollars they pledged five months ago to a humanitarian appeal for Yemen.

Bahraini government loyalists are bragging about how the people are allegedly united in confronting “What is Hidden is Worse” program aired by Al Jazeera channel.