The head of the German armed forces, Inspector General Carsten Breuer, has called for a rapid build-up of missile defence against potential threats from Russia.
"We have five to eight years. We must set up a missile defence system within this period. There is no alternative," Breuer told the Funke Mediengruppe newspapers on Friday.
"We believe that Russia will be able to wage war against NATO states within a time frame of five to eight years. Until then, we in Germany must also be in a position to fend off such an attack," he said.
Russian President Vladimir Putin makes no secret of his intentions towards the West, he said, while adding that an attack on a Western country is currently only a worst-case scenario.
However, it could take place "across the entire spectrum - from cyber attacks to drones and missiles."
He rejected statements in Germany about allowing a frozen conflict in Ukraine.
"Freezing a war presupposes acceptance of this on both sides. There is hardly a frozen conflict in the world that has not flared up again," said Breuer. "The current military situation in Ukraine makes freezing the war seem neither possible nor desirable.
He was reacting to remarks made in parliament earlier this month by Rolf Mützenich, the head of the parliamentary group of Chancellor Olaf Scholz's Social Democrats (SDP).
"Isn't it time we not only talked about how to wage a war, but also thought about how to freeze a war and end it later?" Mützenich said.
He later said the opposition had taken parts of his statement out of context and declared his unwavering support for Ukraine's sovereignty and territorial integrity within its pre-2014 borders.
