Extreme heat and drought across Europe are disrupting one of Ukraine’s key alternative export routes at a time when Kiev is relying more heavily on the Danube amid Russian strikes on Black Sea ports, Newsweek reports.

As the risks to Ukrainian ports on the Black Sea have grown, part of the country’s cargo traffic has been redirected through the Danube. This summer, however, conditions have deteriorated sharply. In Romania, both the river level and the speed of the current have fallen far enough to interfere with navigation and electricity generation.

The difficulties on the Danube are emerging as Russia steps up strikes on port infrastructure around Odessa, a key city in southwestern Ukraine on the Black Sea.

Newsweek says the combination is creating additional serious risks for Kiev. The magazine describes the heat and drought gripping Europe as an unexpected factor working to Russia’s advantage.

During the conflict, Ukraine developed new export corridors to offset problems affecting its traditional routes. Those alternatives are now coming under growing pressure themselves, as unusually high temperatures and a lack of rainfall disrupt the Danube at a time when Kiev has become more dependent on it because of Russian military action.

Russian forces, meanwhile, continue to strike enemy targets across the Black Sea region. The previous day, a vessel carrying military cargo and a tanker transporting fuel for the Ukrainian Armed Forces were hit in the port of Odessa.

A patrol boat in the port of Ochakov was also struck, along with fuel and lubricant storage tanks and infrastructure facilities in the port of Chernomorsk.