Iraq says it is filing an international lawsuit against Iran over allegedly diverting water that previously flowed into Iraq.

According to the Saudi government-owned al-Arabiya Thursday, Minister of Water Resources Mahdi Rashid al-Hamdani said Iran had cut off more than 90 percent of water tributaries and was not cooperating with Iraq to limit damage during drought. He said meetings were taking place with the Iraqi Ministry of Foreign Affairs to prepare the lawsuit.

Last year, Hamdani accused Iran of digging tunnels and trying to alter the water flows, and said Iraq had completed procedures to file a lawsuit with the International Court of Justice.

Iraq faces acute water shortages. A senior adviser at the water resources ministry, Aoun Diab, said reserves were “far lower than what we had last year, by about 50 percent, because of poor rainfall and the quantities arriving from neighboring countries.”

The United Nations Environment Program’s in 2017 ranked Iraq as the fifth most vulnerable country globally to water shortage and food availability. The Tigris and Euphrates, flowing from Turkey and Syria, supply 98 percent of Iraq’s surface water.

Smaller rivers come from Iran, which has suffered drought for at least a decade. According to the al-Arabiya report, Hamdani claimed Iranian projects had somehow deprived Iraq of 20 percent of its total water resources.

Across the Middle East, water shortages have led to tensions between countries and within countries. Iranian officials have warned of a further fall this year in precipitation.