The issue of German cars blew up against a backdrop of concern among United States partners in the G7 club that Trump's "America First" agenda could lead to protectionist measures which could roll back decades of trade liberalisation between the world's most advanced economies.
He said it was "also caused by factors that can not, or at least can not directly, be influenced by economic or financial policy measures in Germany, for example the oil price, the euro exchange rate, but also structural factors such as demographic developments".
Amid the rising trade conflict between the EU and the U.S., Trump announced on multiple occasions his intentions to levy a high punitive tariff on European products.
The president is expected to focus on trade during his visit with world leaders at the G7 Summit in Sicily.
"Some wore the alleged slight as a badge of honour: "#The Germans are very, very bad #Trump. If some reports are to be believed, the temperamental US President allegedly reprimanded Germany for having a massive imbalance in trade with his country, especially with regards to cars.
"He did not say that the Germans were behaving badly", Juncker told reporters in Sicily ahead of G-7 talks.
Trump's reference to Germany's large trade surplus with the United States draws attention to a contentious issue at the summit.
The top issues of the two-day meeting Friday and Saturday are climate change, security, trade and immigration - and the differences between the leaders are substantial.
British Prime Minister Theresa May held up the declaration on fighting terror during a group photo with the other leaders after the document was signed.
Norbert Rottgen, chairman of the foreign policy committee for Merkel's Christian Democratic Union, told Spiegel Online: "US President Trump isn't capable to lead the Western alliance, in any case he isn't interested in it at the moment".
But what did Trump actually say?
The EU is in global trade negotiations with around 20 countries, including Japan, Singapore and Vietnam, seeking to fill the void created by Trump's "America First" policy and the corresponding departure from global trade. He called it a strong message of friendship and solidarity with Britain after the deadly terror attack in Manchester.
His pending review of US climate policies has left environmentalists bracing for the possibility of bland G-7 promises that says little after years of increasingly stronger commitments to reduce reliance on fossil fuels and cut greenhouse gas emissions.