Saudi Arabia's King Salman has called on other countries not to interfere in the kingdom's internal affairs in what appeared to be a rebuke to Riyadh's main foe Iran, which it accuses of attempting to stir unrest.

"It is our right to defend ourselves, without interfering in the affairs of others. We call on others to not interfere in our affairs," King Salman said in a speech opening the annual Janadriya cultural festival in Riyadh.

"We cooperate with our Arab and Muslim brothers in all areas in defending our lands and ensuring their independence and guarding their government systems as sanctioned by their peoples," he added.

King Salman did not elaborate, but his remarks seemed aimed at Iran, which Riyadh accuses of destabilising Arab states and spreading sectarianism by backing militias in Syria, Lebanon, Iraq and Yemen and fomenting unrest in Bahrain and Saudi Arabia.

Iran denies seeking to destabilise the region or incite sectarian hatred. It in turn accuses Riyadh of fomenting discord by backing rebels in Syria, going to war in Yemen and propagating an ultra-conservative Sunni Muslim school that declares Shi'ites heretical.

The Saudi king, who succeeded to power a year ago after the death of his half-brother Abdullah, brought together a coalition of Arab states to back military action in Yemen to restore its government after it was ousted by an Iran-allied militia.