The WaPO reported on Friday adding that President Donald Trump has already discussed the proposal, which has worried European Nato allies, with military officials.

Citing anonymous sources, the Post stressed that the study was only an internal examination of options at this stage.

Among the options under consideration are repatriating a large contingent of the approximately 35,000 active duty troops, or a full or partial move of the military personnel from Germany to Poland, AFP notes.

However, a White House National Security Council spokesman denied any such analysis. Pentagon spokesman Eric Pahon also denied any plans for a withdrawal.

"The Pentagon regularly reviews force posture and performs cost-benefit analyses," he said in a statement.  "This is nothing new. Germany is host to the largest US force presence in Europe -- we remain deeply rooted in the common values and strong relationships between our countries. We remain fully committed to our Nato ally and the Nato alliance."