Iran stood firm Sunday on its conditions for reopening the Strait of Hormuz, despite U.S. President Donald Trump's rejection of the proposal that had created some optimism for breaking the Mideast war stalemate.

The waterway is key to the world's energy supply and is now central to the conflict between Washington and Tehran, which was triggered nearly seven months ago with deadly strikes on Iran.

Parents across Riyadh received emails from schools on Sunday announcing a last-minute plan to shift to remote learning for a week, according to messages seen by AFP.

"We have just been informed by Saudi authorities that schools must remain closed all week," read two separate messages seen by AFP.

Prime Minister Nawaf Salam insisted at the U.N. on the need to "avert the vacuum" that would be caused by withdrawing the peacekeeping mission deployed in the country's south without a viable replacement.

Under U.S. pressure, the U.N. Security Council decided last month to fix December as the end of the mandate of the United Nations Interim Force in Lebanon (UNIFIL), which has been deployed since 1978.

The Iraqi government said Saturday it was holding talks with the United States to secure an exemption from then ban on Iranian airlines, which has disrupted travel for patients, students and pilgrims.

All Iraqi airports enforced the ban this week, resulting in major disruption at the airport of the holy city of Najaf, the main destination for Iranian flights to Iraq.

The United States had yet to publicly respond on Saturday after Iran offered a plan to reopen the strategic Strait of Hormuz, though reports indicated that President Donald Trump had rejected the proposal.

China and the United States agreed to set up a "communication channel" for artificial intelligence incidents, both sides said, after a Washington summit short on breakthroughs.

Saudi Arabia, Turkey and Pakistan will hold chief of staff talks to support the kingdom, Riyadh said in a statement on Friday, as Yemen's Houthis ramp up attacks on the world's top crude exporter.

The Iran-backed group has escalated its attacks on the kingdom since July, ending a years-long truce and declaring a maritime blockade, hitting Saudi targets and seizing Yemen's entire Red Sea coast as they seek to stifle Saudi oil exports.

In southern Lebanon, eight-year-old Yara Ajami started the academic year this week in a doorless, windowless classroom after her school was destroyed by an Israeli strike.

Well known in the area for its excellence, Ajami's elementary school in Burj Qalaway was struck by Israel in May.

Russia on Friday said a Ukrainian strike killed three people -- which it said were aid volunteers from Siberia -- in the Moscow-occupied part of the southern Ukrainian Zaporizhzhia region.

Kremlin-installed official Yevgeny Balitsky said "three volunteers from (Russia's) Omsk region were killed as a result of a cynical terrorist attack on a civilian vehicle delivering humanitarian aid" near the village of Novobogdanivka.

The four main European football leagues -- the English Premier League, Spain's La Liga, Italy's Serie A and Germany's Bundesliga -- called on Friday for a reform of FIFA.

The sport's governing body has been mired in crisis since the revelation of a shelved plan to create a commercial company open to private investors.