US Secretary of Defence, Secretary Mark Esper has denied US troops are pulling out of Iraq, after a letter from a US general there suggested a withdrawal.
The letter said the US would be "repositioning forces in the coming days and weeks" after Iraqi MPs had called for them to leave.
Mr. Esper said there had been "no decision whatsoever to leave".
The confusion came amid threats to American forces after the US killed top Iranian commander Qasem Soleimani.
He died in a US drone strike in Baghdad on Friday on the orders of Mr. Trump.
The killing has sharply increased regional tensions, with Iran threatening "severe revenge".
What was in the letter?
It appeared to have been sent by Brig Gen William H Seely, head of the US military's task force in Iraq, to Abdul Amir, the deputy director of Combined Joint Operations.
It starts: "Sir, in due deference to the sovereignty of the Republic of Iraq, and as requested by the Iraqi Parliament, and the Prime Minister, CJTF-OIR (Combined Joint Task Force - Operation Inherent Resolve) will be repositioning forces over the course of the coming days and weeks to prepare for onward movement."
The letter says certain measures, including increased air traffic, will be conducted "during hours of darkness" to "ensure the movement out of Iraq is conducted in a safe and efficient manner".
It would also "alleviate any perception that we may be bringing more Coalition Forces into the IZ (Green Zone in Baghdad)".
