The move would reduce the US force presence in Germany by about 28%, pulling back 9,500 from the 34,500 who are now there.
Merkel's decision to stay away from a Group of Seven meeting that Trump had planned to host in Washington this month had no influence on the planned pullout, the person said.
The move also limits the size of US troops deployed in Germany at any one time at the 25,000-troop level.
"I don't want to speculate on something for which I have no confirmation", Defence Minister Annegret Kramp-Karrenbauer told a news conference on Monday.
No details have been offered about exactly which troops would be withdrawn, what bases they would be withdrawn from, or where they would be sent.
Germany hosts more United States troops than any other country in Europe, a legacy of the Allied occupation after World War II.
What they do understand is that the current occupant of the Oval Office is a long-time skeptic about South Korea generally; enjoys poking the South Korean government in the eye, and at one point ordered the Pentagon to withdraw the family members of USA military personnel from the country.
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The unemployment rate for black workers edged up to 16.8% in May from 16.7% in April and for Asian workers it rose to 15% from 14.5%.
A top German official said it was "unacceptable" - a move that could impact the long-standing relationship between the North Atlantic Treaty Organisation allies. "So we're protecting Germany, we're protecting France, we're protecting all of these countries".
"I predict there will be no withdrawal of these soldiers", John Kornblum, who represented the USA in Berlin from 1997 to 2001, told the Passauer Neue Presse newspaper on Monday. Those bills never emerged.
The Pentagon referred Axios to the White House for comment.
"But the damage is certainly done to some degree on the relationship", Hodges told DW. "I believe this is a colossal mistake", said Hodges. On top of this, Hodges is anxious about the message about American commitment such a move would send to both "allies and potential adversaries".
Opposition Greens veteran politician Jürgen Trittin accused Trump of having floated the withdrawal plan to sway the upcoming U.S. presidential election. Unlike Germany, a master at excuse-making for failing to meet its 2% GDP threshold on defense spending and whose air force is unprepared for combat, Seoul has been pouring money into procurement for years. Many Germans in the area also regard the long-term military presence with affection. "Maybe we can see a change here", he said.
Speaking the day before the London meeting, Mr. Stoltenberg touted the recent increase in US troops in Europe as evidence of USA commitment.
Maas acknowledged problems in Germany's relationship with the United States, saying: "We are close partners in the transatlantic alliance".
As well as serving as a deterrence to a resurgent Russia, US troops use their German bases to coordinate military operations in Europe, Africa and the Middle East.