Riyadh has accused Iran of supplying the Houthis with the weapon used in the June 13 attack on Abha airport. Tehran and the Houthis deny coalition charges that Iran supplies the Houthis with missiles and drones.
The experts painted grim picture of a "deeply fractured" country sliding toward "humanitarian and economic catastrophe" with no sign of victory by either side in a conflict that many view as a proxy war between regional rivals Saudi Arabia and Iran.
The attack marked the third time in five months that missiles have flown over Riyadh, as the Houthis step up efforts to demonstrate they can reach the Saudi capital, and threatened to escalate a regional rivalry between Iran and Saudi Arabia.
The officials said on Friday that the Houthis said they would not resume talks unless the U.N. condemned government breaches of the week-long truce. Houthi fighters have also ignored the cease-fire agreement.