In their campaign program for the German election, Chancellor Angela Merkel's conservatives have dropped the term "friend" in describing the relationship with the United States. Four years ago, the joint program of her Christian Democratic Union (CDU) and its Bavarian sister party, the Christian Social Union (CSU), referred to the United States as Germany's "most important friend" outside of Europe.

German Chancellor and head of the Christian Democrats party, Angela Merkel and the leader of the CDU's Bavarian sister Party CSU (not in picture) give a press conference on July 3, 2017 in Berlin. Odd Andersen | AFP | Getty Images

The 2013 program also described the "friendship" with Washington as a "cornerstone" of Germany's international relations and talked about strengthening transatlantic economic ties through the removal of trade barriers. But the words "friend" and "friendship" are missing from the latest election program - entitled "For a Germany in which we live well and happily" - which Merkel and CSU leader Horst Seehofer presented on Monday ahead of a Sept. 24 election.

Instead, the United States is described as Germany's "most important partner" outside of Europe. CDU officials were not immediately available to comment on the change in wording. The change in wording underscores how relations between Berlin and Washington have deteriorated since U.S. President Donald Trump entered the White House in January. During his campaign for the presidency, Trump said that Merkel was "ruining" Germany with migration policies he described as "insane." He has repeatedly denounced Germany's trade surplus with the United States, accused Berlin and other European partners of owing "massive amounts of money" to NATO, and unsettled western partners with his decision last month to pull out of the Paris climate accord. A survey by the Pew Research Center last week showed that just 35 percent of Germans have a favorable view of the United States, down from 57 percent at the end of President Barack Obama's term. Merkel is due to host Trump and other leaders at a G20 summit in Hamburg later this week.