Baghdadinfo-icon: Seventeen hours after the USinfo-icon military in Iraqinfo-icon told the government that American troops were preparing to pull out of the country as Iranian threat of an impending retaliation over the assasination of its top military commander in Baghdad looms, a senior US general in Washington said the message was sent by "mistake".

The head of the US military's Task Force Iraq, Brigadier General William Seely, informed his Iraqi counterparts in a letter dated Sunday that troops were preparing to leave.

The letter was sent soon after Iraq's Parliament voted to expel US and coalition troops from the country.

The expulsion vote came soon after Trump ordered the assassination of Iranian general Qassem Soleimani on Iraqi soil.

"We respect your sovereign decision to order our departure," said the letter, whose authenticity was confirmed by both Iraqi and US defence officials.

Seely said the US-led coalition would "be repositioning forces over the course of the coming days and weeks".

"In order to conduct this task, Coalition Forces are required to take certain measures to ensure that the movement out of Iraq is conducted in a safe and efficient manner," said the letter.

It said helicopters would be travelling in and around Baghdad's Green Zone where the US embassy is located as part of the preparations.

Foreign journalists based in Iraqi capital could hear helicopters flying low over Baghdad throughout the night on Monday.

But Pentagon Joint Chiefs Chairman Mark Milley said on Monday the letter was a mere "draft" and "should not have been sent".

"This was a mistake," Milley told reporters. "It was a mistake, an honest mistake, a draft unsigned letter, because we are moving forces around," he said.

"It shouldn't have been sent," Milley said.

US Defence Secretary Mark Esper said the letter was "inconsistent" with Washington's position, denying there has been a decision to leave Iraq.

The latest developments came as a sea of mourners paid homage across Iraninfo-icon to General Qasem Soleimani, the head of the Revolutionary Guards' Quds Force killed Friday in a US drone strike in Baghdad.

Following his death along with Iraqi military figure Abu Mahdi al-Muhandis, Iraqi parliament on Sunday passed a resolution calling for the government to oust all US led forces from Iraqi soil.

Trump threatens 'retaliation'

Thousands of US soldiers are stationed across Iraqi bases.

Trump vehemently denounced the Iraqi parliament's resolution, telling reporters on Air Force One on Sunday that the U.S. would "charge them sanctions like they've never seen before" if U.S. troop withdrawals were not initiated in a "friendly" manner. 

"If there's any hostility, that they do anything we think is inappropriate, we are going to put sanctions on Iraq, very big sanctions on Iraq," Trump added.

The targeted killing of the 62-year-old Soleimani ordered by US President Donald Trumpinfo-icon saw Iran vow "severe revenge" and step back even further from the already tattered 2015 nuclear accord with worldinfo-icon powers.

In an escalating warinfo-icon of words that has heightened international concern and rattled financial markets, Trump threatened yet more "major retaliation" if Tehraninfo-icon hits back, including strikes on Iranian cultural sites.

Writing in all-caps on Monday, Trump tweeted: "IRAN WILL NEVER HAVE A NUCLEAR WEAPON!"


Meanwhile senior US administration officials have reportedly begun drawing up potential economic sanctions against Iraq in the wake of President Trumpinfo-icon's threat to impose sanctions should the country force American troops to withdraw.

The talks regarding possible sanctions are in preliminary stages, The Washington Post reported, citing three officials briefed on the planning. The officials stressed that no final decision has been made regarding economic penalties. One said that the plan was to wait "at least a little while" to see if Iraq followed through with its calls to expel U.S. troops from the country. 

The officials added that the Treasury Department and the White House would orchestrate the sanctions effort on Iraq, a foreign ally the U.S. has invested billions supporting, if it were to move forward. 

The White House and the Treasury Department did not immediately respond to a request for comment from The Hill.