Gulf Arab leaders arrived in Saudi Arabia on Tuesday for a summit focused on ending a long-running dispute with Qatar which shattered Gulf unity at a time of heightened regional tensions with Iran.

Qatar's Emir Sheikh Tamim bin Hamad al-Thani was met in the historic city of al-Ula by Saudi Crown Prince Mohammed bin Salman. The two men, wearing face masks, embraced on the tarmac.

Ahead of the gathering, Kuwait announced that Saudi Arabia, which along with allies boycotted Doha in mid-2017, would reopen its airspace and borders to Qatar under a deal that a senior U.S. official said would be signed in the presence of White House senior adviser Jared Kushner.

Other Gulf leaders arrived earlier and Egypt's foreign minister would also attend the annual summit, postponed from its December date as Riyadh worked for a deal.

Saudi Arabia, the United Arab Emirates, Bahrain and Egypt severed diplomatic, trade and travel ties with Qatar over allegations Doha supports terrorism, a charge it denies.

The breakthrough is the latest in a series of Middle East deals sought by Washington - the others involving Israel and Arab states - aimed at building a united front against Iran.

While Riyadh made clear it intended to lift the embargo, the other three states did not immediately comment on the issue. But the U.S. official said "it's our expectation" they would also join. Under the emerging deal, Qatar will suspend lawsuits related to the boycott, the official said.