U.S. Army tanks recently deployed to Europe arrived at a port in Germany, some of them with dead batteries and without sufficient fuel.

The Wall Street Journal reported this week on logistical challenges that the U.S. military faced when sending an armored unit of 4,000 soldiers and 90 tanks to Europe in order to protect NATO member states and deter Russian aggression.

Lt. Gen. Ben Hodges, the commander of U.S. Army Europe, revealed that some of the tanks arrived in the port city of Bremerhaven, Germany, with dead batteries as a result of a mistake by the contractor. Some of the tanks also did not have full fuel.

"It is stuff we used to know," Hodges told the Journal.

Defense officials revealed in December that the United States was accelerating its deployment of troops to Poland, the Baltic states, and Romania. The unit of soldiers arrived in Germany in early January, after which they were to move to Poland and then to Estonia, Latvia, Lithuania, and Romania. At the time, Hodges described the transfer as a test of "how fast the force can move from port to field."

Five of the Army's heavy vehicles sent to Germany were still sitting at the port as military officers were still figuring out how to move them eastward to Poland, the Journal reported on Tuesday.

Separately, NATO partners finalized a deal last year to send four multinational battalions to the Baltic states and Poland to deter Russian aggression like that displayed in Ukraine. The battalions are led by the United States, Britain, Canada, and Germany.

Russia has declared NATO deployments in eastern Europe a threat to its national security, and has promised to bolster its own forces in response.