Qatar's Prime Minister Sheikh Mohammed bin Abdulrahman bin Jassim Al-Thani has warned that an attack on Iran's Gulf coast nuclear facilities would leave countries across the region without water.

In an interview with right-wing United States media personality Tucker Carlson, who is close to US President Donald Trump, the premier said Doha had simulated the effects of an attack.

The sea would be "entirely contaminated" and Qatar would "run out of water in three days," he said.

The construction of reservoirs since then had increased water capacity, he added, but the risk remained for "all of us" in the region.