KYIV, July 26 (Reuters) - Russia said it will cut gas supplies to Europe from Wednesday in a blow to countries that have backed Ukraine, while missile attacks in Black Sea coastal regions raised doubts about whether Russia will stick to a deal to let Ukraine export grain.

The first ships from Ukraine may set sail in days under a deal agreed on Friday, the United Nations said, despite a Russian missile attack on the Ukrainian port of Odesa over the weekend, and a spokesman for the military administration in the saying another missile had hit the Odesa region on Tuesday morning.