Iranian President Hassan Rouhani has accused archrival Saudi Arabia of promoting poverty and terrorism by continuing to bomb Yemen and supporting armed rebels fighting to topple Syrian President Bashar Assad in Syria.

Addressing a conference in Tehran, Rouhani suggested that destroying Syria won't strengthen Turkey, Jordan, Saudi Arabia, Qatar and the United Arab Emirates, a reference to governments supporting the anti-Assad rebels.

Iran is one of Assad's main allies and has provided his government with military and political backing for years.

Rouhani also said a Saudi-led coalition that has been bombing Yemen since March has led to a humanitarian crisis and greater poverty in Yemen, the main causes behind the spread of extremism.