The Saudi-led air war on Yemen was launched to foil a plot by a "sectarian group" to undermine security in the region, King Salman said on Sunday.
The Saudi monarch was defending the military operation Riyadh has led against Yemen rebels since March 26, in an address read to clerics on his behalf by an adviser in the Muslim holy city of Mecca.
The operation has prevented Yemen from "becoming a theatre for terrorism, discord, and internal fighting, similar to some countries," said Salman, in remarks published by the official SPA news agency.
Saudi Arabia wanted to "support Yemen and confront the attempt to transform it into a base for launching a plot to undermine regional security and stability", he said.
The kingdom and members of the coalition began the campaign to "save Yemen and its brotherly people from a group entrenched with the spirit of sectarianism", Salman said, referring to the Shia Houthi rebels.
He said the rebels had "threatened neighbouring countries, especially Saudi Arabia, with backing from foreign parties seeking to spread their influence across the region and sow sedition", implying Iran.
This is an example of "using sectarianism to achieve political" goals, he said.
The Houthis were also "backed by internal Yemeni groups that broke their agreements," he said of Yemen's former president Ali Abdullah Saleh whose loyalists have been fighting alongside the Houthis.
Saleh resigned in 2012 under a Saudi-backed deal following a year-long uprising against his rule.
Sunni Saudi Arabia accuses its Shia rival Iran of attempting to expand its zones of influence across the region.
Tehran has repeatedly criticised the Saudi-led intervention in Yemen.
Riyadh responded to "this danger after exhausting all peaceful means to find a solution in Yemen," King Salman said