Celebrities including Jack Black, Morgan Freeman and Natasha Lyonne have come together in a video call urging Americans to back the Iran deal.

Other proponants of the deal on the video include former CIA agent Valerie Plame, retired U.S. Ambassador Thomas Pickering and Queen Noor of Jordan.

In a video that appears at first glance to be a spoof ad, the celebrities encourage US citizens to contact their members of Congress to back the deal, which would be up for a vote in September.

Jack Black says "a deal with Iran is the only way to guarantee Iran doesn't build a bomb" which would be like "a really dark unpleasant cloud of death toast".

Lyonne then tells viewers that war with Iran is "the worst idea ever..."