Saudi Arabia has raised concerns about Israel's refusal to join a United Nations nuclear non-proliferation treaty, saying it was an obstacle to achieving peace in the region.

The warning was a rare moment of Saudi criticism of Israel, with Riyadh and other Gulf countries recently working together, along with Israel, to combat Iran's nuclear programme.

Saudi Arabia's new permanent representative to the United Nations, Abdulaziz al-Wasil, made the comments on Wednesday during a conference to review the UN's Non-Proliferation Treaty.