Vice Admiral Kay-Achim Schoenbach stepped down as the head of the German navy after publicly saying Crimea was lost to Ukraine and that Vladimir Putin "probably" deserved respect, DW reported.
"I have asked Defense Minister Christine Lambrecht to relieve me from my duties with immediate effect," Schoenbach said in a statement cited by the Reuters news agency.
"The minister has accepted my request," he added.
Schoenbach made the comments during a talk that he gave in a visit to India. Speaking at the Manohar Parrikar Institute for Defence Studies and Analyses, the German vice admiral said Putin "probably" deserved respect.
"What he really wants is respect," the vice admiral said, speaking in English in remarks that were posted on a video on YouTube.
"And, my God, giving someone respect is low cost, even no cost. ... It is easy to give him the respect he really demands—and probably also deserves," Schoenbach said, calling Russia an old and important country.
Schoenbach said Russia's actions in Ukraine needed to be addressed, but added that "the Crimea Peninsula is gone: It will never come back—this is a fact."
The remarks directly contradicted the official view held by the EU and the US. Washington and its allies say that Moscow's 2014 annexation of the peninsula from Ukraine was unacceptable and must be reversed.
On Saturday, Ukraine's Foreign Ministry said it has summoned German Ambassador Anka Feldhusen to stress "the categorical unacceptability" of Schoenbach's comments.
The German government made no official statement, although it distanced itself from Schoenbach's comments on Saturday.
"The content and choice of words of the statements in no way correspond to the position of the Federal Ministry of Defense," a German Defense Ministry spokesman told public broadcaster ZDF.
Schoenbach must now explain himself to his superior, Inspector General Eberhard Zorn, the ministry said. Additionally, Germany's ruling coalition will discuss the navy chief's statements on Monday, ZDF reported.
For his part, Schoenbach issued an apology on his Twitter account. "There is no need to quibble: it was clearly a mistake," he tweeted.
"My defense policy remarks during a talk session at a think tank in India reflected my personal opinion in that moment. They in no way reflect the official position of the defense ministry," he wrote.
The Ukrainian Foreign Ministry called on Germany to reject Schoenbach's comments regarding Crimea, saying they undermine the efforts to counter Russian aggression.
"Ukraine is grateful to Germany for the support it has already provided since 2014, as well as for the diplomatic efforts to resolve the Russian-Ukrainian armed conflict. But Germany's current statements are disappointing and run counter to that support and effort," Ukrainian Foreign Minister Dmytro Kuleba said on Twitter.
"The German partners must stop undermining unity with such words and actions and encouraging (Russian President) Vladimir Putin to launch a new attack on Ukraine," Kuleba added.
Kyiv also highlighted its "deep disappointment" at the German government's position "on the failure to provide defense weapons to Ukraine." The lack of weapons support is another point of contention between the two countries.
On Friday, reports emerged about Germany blocking Estonia from sending its German-made weapons to Ukraine.
Berlin has long argued that it does not support sending weapons to active conflict zones and stressed that such deliveries would hinder negotiations and a peaceful resolution to the crisis.