The leader of Germany's Social Democrats, Martin Schulz, who will confront Chancellor Angela Merkel in September elections, on Tuesday became the latest German politician to join in a war of words with Washington.

Schulz described US President Donald Trump as "a destroyer of all Western values such as we have never before experienced in this form."

Trump's destructive strategy targeted, tolerance, respect and cooperation between peoples on the basis of mutual acceptance, Schulz said. 

Schulz' comments came shortly after Foreign Minister Sigmar Gabriel unleashed a barrage of criticism against Trump's administration, following the widely publicized remarks by German Chancellor Angela Merkel.

Read: Merkel makes waves with views on EU-US relations.

Gabriel spoke of the US "dropping out as an important nation."

"That's unfortunately a signal for a change in the world's balance of power," he said.

Gabriel also criticized the Trump administration for selling weapons to Saudi Arabia, its refugee policy, and its lack of commitment to fight climate change. Gabriel, who also serves as Germany's vice chancellor, said that "anyone who accelerates climate change by weakening environmental protection, who sells more weapons in conflict zones and who does not want to politically resolve religious conflicts is putting peace in Europe at risk."

"The short-sighted policies of the American government stand against the interests of the European Union," he said at the refugee conference, adding that the West "became weaker."

Trump wades in again, too

Gabriel's center-left SPD party is a partner to Angela Merkel's CDU in Germany's current ruling coalition, but the two groups are also set for a showdown in general elections in September. The growing rift between Berlin and Washington under Trump marks a sharp contrast in comparison to mostly close relations under former president Barack Obama.

Trump on Tuesday himself made another Twitter contribution to aggravating the divide between the two countries, again accusing Germany of putting the US at a disadvantage with its trade surplus, and failing to make enough payments to NATO.

Read: Trump launches new Twitter tirade against Germany

Americans out, China in?

In German public broadcaster ZDF's main evening news show, Gabriel restated his complaints, focusing on Trump's behavior during his recent diplomatic tour.

Specifically, he said Trump "lectured his colleagues and notably shoved a prime minister aside" at a NATO summit. The minister also lamented Trump ''moving away from Western ideas," including international law.

"American colleagues apparently do not realize that, when they leave, there are others who are coming in, for example China, with completely different ideas."

Germany to help others

In response to the crisis, Europe should be "sticking together and growing stronger" and defend the ideas of democracy, liberalism, and openness, he said. Germany should also do more to help countries like France and Italy to reach their economic potential, according to Gabriel.

"Most importantly, we need to stop demeaning or lecturing others," he added.

dj/rg (AFP, Reuters, AP, dpa)