Saudi Arabia's King Salman has vowed to prevent other nations from intervening in neighboring Yemen, where it has been at war with Iranian-backed Shiite rebels since March 2015.

The televised speech at the start of a meeting of his top advisory council on Wednesday included no major policy changes despite regional upheaval and the economic challenge poses by low oil prices.

Salman says Saudi Arabia remains committed to diversifying its economy based on the Vision 2030 roadmap, which includes slashing public spending, reducing reliance on oil revenue and boosting employment in the private sector.

Saudi Arabia views Iran as its main regional rival, and the two support opposite sides in the wars in Yemen and Syria.