Confusion gripped the US-led Coalition in Iraq last night after a leaked letter from America’s military suggested it was preparing to withdraw its forces.

But it later emerged the withdrawal was just of several hundred troops from Baghdad's protected Green Zone for "force protection" reasons.

The earlier announcement from the US Defence Department suggested that members of the Combined Joint Task Force – Operation Inherent Resolve, which is the US-led coalition against the so-called Islamic State terror group, and which includes British troops, would be withdrawn soon.

It came just a day after Iraqi MPs demanded the removal of all foreign soldiers in the wake of the killing on Iraqi soil of Iran’s top general Qasem Soleimani.

In a letter to the Iraqi Defence Minister, Brigadier General William Seely, head of US forces in Iraq, said in “deference to the sovereignty of Iraq” and the request made by Iraqi MPs and the country’s Prime Minister, Adil Abdul-Mahdi, the Joint Task Force will be “repositioning forces over the coming days and weeks to prepare for onward movement”.

Gen Seely noted that during this period there would be increased traffic, which would include security escort helicopters, under cover of darkness “to help alleviate any perception that we may be bringing more Coalition forces into the IZ[International Zone]”.

He added: “We respect your sovereign decision to order our departure.”

However, Mark Esper, the US Defence Secretary, denied US troops were being pulled out of Iraq.

"There's been no decision whatsoever to leave Iraq. I don't know what that letter is,” he declared.

“We're trying to find out where that's coming from; what that is but there's been no decision made to leave Iraq. Period," he added.

Coalition sources last night suggested that the announcement would involve not the full force of more than 5,000 Coalition troops but merely some 500, about half the complement of the allied taskforce in Baghdad’s heavily fortified Green Zone, which houses Government buildings and foreign missions.

One source suggested the move was meant to better protect allied forces from attack by Shia militias. Troops would be dispatched elsewhere in Iraq and to Kuwait.

Another insider explained the move was meant to “thin out” Coalition forces in the Iraqi capital. “We’re not leaving Iraq,” he insisted.

However, any movement of Coalition forces away from Baghdad will give heart to America’s enemies in Iran and within the remnants of the so-called Islamic State terror group.

The development appeared to catch the Ministry of Defence on the hop. One Whitehall source noted: “This is not what we were hearing from the Pentagon today.”

The confusion over troop withdrawal is set to feature highly when MPs are updated on the Persian Gulf crisis today in an expected Commons statement from Dominic Raab, the Foreign Secretary.

Given concerns have already been raised after the UK Government was not pre-warned by Washington about the killing of Gen Soleimani, further questions will be asked about whether or not Downing St was informed of the planned troop withdrawal from Baghdad given the highly volatile nature of the situation there.

In a separate development, Sky News reported that Britain had reduced staff at its embassies in Iran and Iraq to a minimum level amid security concerns following the killing of Gen Soleimani.

At home, the UK Government doubled down on its warning to Donald Trump not to act on his threat to launch an attack on Iran’s cultural sites, which would breach international conventions and be regarded as a war crime.

Mr Raab distanced Britain further from the US President’s bellicose rhetoric.

Emerging from a ministerial meeting on Iran, the Foreign Secretary stressed: “We have been very clear that cultural sites are protected under international law and we would expect that to be respected."

This followed an earlier reference from No 10 to the 1954 Hague Convention for the protection of cultural property in the event of armed conflict was drawn up under the auspices of the United Nations.

Its guiding principle is that “any damage to cultural property, irrespective of the people it belongs to, is a damage to the cultural heritage of all humanity, because every people contributes to the world's culture”.

Boris Johnson’s spokesman, when asked about Mr Trump’s threat to Iran’s cultural sites, made clear: “There are international conventions in place that prevent the destruction of cultural heritage.”

The President has said suggested that if Tehran ordered retaliation for the killing of Gen Soleimani, then action could be taken against 52 sites, some of which he said were "at a very high level and important to Iran and the Iranian culture".

This figure matches the number of American hostages held by Iran in 1979, when a group of US diplomats and citizens were detained for 444 days in Tehran.

On Sunday Mr Trump told reporters: “They're allowed to use roadside bombs and blow up our people and we're not allowed to touch their cultural sites? It doesn't work that way."

This morning the PM will chair his first Cabinet of the year, which is set to discuss the Persian Gulf crisis. Later, the National Security Council will meet to discuss the issue.

On Monday, Mr Johnson spoke on the phone to Adel Abdul-Mahdi, his Iraqi counterpart, and they agreed to "work together to find a diplomatic way forward" to the Iran crisis.

No 10 said: “The leaders discussed the need to de-escalate tensions in the region following the death of Gen Soleimani and agreed to work together to find a diplomatic way forward.

“The Prime Minister underlined the UK’s unwavering commitment to Iraq’s stability and sovereignty and emphasised the importance of the continued fight against the shared threat from Daesh,” it added.

Earlier, Mr Johnson’s spokesman was asked about the PM’s reaction to not being told in advance of the US drone strike that killed Gen Soleimani last Thursday at Baghdad Airport.

He replied: "We have a very close security partnership with the United States; we are in regular dialogue at every level."

On Monday, huge crowds packed the streets of Tehran for the funeral of Gen Soleimani.

Ayatollah Khamenei, Iran's Supreme Leader, led prayers and at one point was seen weeping.

Today, an enormous gathering is expected for the military commander's burial in his home town of Kerman.