Guiding the yen lower would hurt other Asian economies, Bundesbank President Ernst Welteke told Japanese news agency Jiji on Thursday.
The comment helped the yen rise modestly in the foreign exchange market which had been selling the currency recently partly on speculation Japan would take fresh steps to drive it lower.
Earlier on Thursday, Economics Minister Heizo Takenaka said it was worth the Bank of Japan considering buying foreign bonds, one of many proposals for weakening the yen.
However, the BOJ has long argued that actively pushing the yen lower would not be welcome in the rest of Asia since it would put pressure on regional currencies to depreciate to remain competitive.