REVEALED: The 60,000 US troops already based in Europe that Biden can use to defend Ukraine against Russia: President orders extra 8,500 US-based troops to be on standby to deploy and places USS Harry S Truman under NATO control

 Nearly 64,000 U.S. troops stationed in Europe could be deployed to the continent's eastern flank if President Biden makes such a call to counter growing Russian aggression at the border with Ukraine. 

The USS Harry S. Truman has already been placed under NATO command for the first time since the end of the Cold War, while 40 warships, 175 aircraft and 90 tanks situated throughout Europe could also be readied for conflict.

Biden has ordered 8,500 U.S.-based troops to stand ready to deploy to Eastern Europe, while military officials have presented him with a plan to send 50,000 more if the security situation deteriorates and Russia launches an invasion into Ukraine. 

At the same time, the US told families based at the US embassy in Kiev to go home 'due to the continued threat' of such an attack, the State Department said Sunday. 

Though the number fluctuates due to changing withdrawals and deployments, the U.S. had about 175,000 troops stationed abroad as of September 2021. A total of nearly 64,000 of those service members were stationed in Europe. 

The U.S. has about 750 military bases across 80 countries. 

Command for the U.S.'s 40 warships is based out Italy, and the U.S. has already flexed its muscle to Russia by sending ships to the politically fraught Black Sea. 

Germany houses the largest deployment of U.S. troops in Europe, and only Japan and America have more U.S. troops based there. There are 35, 468 U.S. troops in Germany - 21,585 Army, 13,009 Air Force and small numbers of troops from the Marine Corps and Navy.  

As the imminent threat of war looms over Europe, it comes as: 

• The USS Harry S. Truman and its strike group will participate in a NATO exercise in the Mediterranean until February 4;
• Biden said he and European leaders had 'total unanimity' about the situation in the Ukraine;
• The White House said NATO has emphasised a desire for a diplomatic solution;
• Putin discussed a 'strategic partnership' with Cuba in a phone call with President Miguel Díaz-Canel, days after fears were raised that Russia would deploy military to South America;
• The US and UK have begun withdrawing diplomats from their embassiesin Kiev.

The USS Harry S. Truman is already being placed under NATO command for the first time since the end of the Cold War (pictured)

There are 21 U.S. military bases across Germany, with the largest presence at Stuttgart, headquarters of United States European Command (EUCOM) and US Africa Command, and Ramstein, headquarters of US Air Force operations in Europe. 

And while Germany previously housed some 5,000 U.S. tanks in the height of the Cold War in 1989, it is now permanent home to none. 

The Army temporarily deploys one armored brigade at a time, each on a nine-month rotation. A typical armored brigade is made up of 90 M-1 tanks and 130 Bradley fighting vehicles plus around 18 M-109 self-propelled howitzers. 

But there remains a problem: Europe's aging bridges may not be ready for the 68-ton M-1 Abrams tanks. The Army has been struggling to purchase more armored bridge-layers to help these heavy vehicles pass. 

The M-1 Abrams has been in use in war zones since 1980, while the Bradley fighting vehicle is a heavily armed and armored troop transporter that launches fire toward enemy lines to provide cover. The Howitzer is a 30-ton gun that can hit targets up to 19 miles away.  

And while NATO has a presence of about 130 tanks, including the 90 U.S. vehicles, Russia, even before its recent aggression, kept about 760 tanks within striking distance of NATO's Baltic members. 

Ukraine shares a border with four NATO countries: Poland, Slovakia, Hungary and Romania. 

Italy has the second highest U.S. presence in Europe, with 12,436 troops, 4,081 belonging to the Army, 4,742 Air Force and 3,497 Navy. The Naples port is the headquarters of the Sixth Fleet, or US Naval Forces Europe-Africa. 

The Aviano Air Base is home to two U.S. F-16 fighter jet squadrons. The F-16 is a popular air-to-air combat jet used by 25 air forces.  

In the United Kingdom there are 9,576 U.S. troops, almost entirely members of the Air Force with small numbers of service members from other branches. 

Spain has 3,423 U.S. troops stationed there, Belgium has 1,143, Greece has 429, Portugal has 259, and Romania has 132. A handful of other nations have a U.S. troop presence smaller than 100. 

There are also currently more than 150 U.S. military advisers in Ukraine who have operated at a training ground near Lviv for years. It includes Special Operations forces, mostly Army Green Berets, and National Guard trainers from Florida's 53rd Infantry Brigade Combat Team.

While the U.S. intends to move its military trainers out of Ukraine swiftly should a full-scale Russian invasion occur, it's also possible some American forces could stay to advise Kyiv officials and provide frontline support, a U.S. official told the Times. 

However, roughly 6,000 U.S. troops are deployed to Eastern Europe on a rotating basis, including about 4,000 are currently in Poland. 

The U.S. Sixth Fleet, which leads European Command, is comprised of roughly 175 aircraft and 40 warships. European Command is headquartered in Germany.   

Biden's potential plan would see between 1,000 and 5,000 soldiers sent to NATO nations such as Lithuania, Estonia and Latvia, which border Russian territory.

Troop numbers could then be increased up to 50,000 if the security situation deteriorates, backed up by fresh deployments of ships and aircraft.

The plan would not involve American troops deployed directly to Ukraine, with Biden thought to be loathe to enter another conflict following his disastrous withdrawal of U.S. troops from Afghanistan last year, The New York Times reports. 

Meanwhile the Biden administration is ordering 8,500 U.S.-based troops to stand ready to deploy to Eastern Europe, the Pentagon announced on Monday. 

The 68-ton M-1 Abrams has been in use in war zones since 1980

The Aviano Air Base is home to two U.S. F-16 fighter jet squadrons. The F-16 is a popular air-to-air combat jet used by 25 air forces

A Russian rocket launcher fires during military drills near Orenburg in the Urals, Russia in December. With tens of thousands of Russian troops positioned near Ukraine, the Kremlin has kept the U.S. and its allies guessing about its next moves in the worst Russia-West security crisis since the Cold War

The NATO Response Force is comprised of some 40,000 international troops across land, air, maritime and Special Operations Forces (SOF) components. 

'This is really about getting folks ready to go,' Defense Department spokesman John Kirby said during a press conference this afternoon. He said the majority of those troops would be ground forces.

He said they would stand ready in case NATO activates the NATO Response Force (NRF) or in the event of a 'deteriorating security environment.'

NATO meanwhile announced Monday that its members were to deploy additional ships and fighter jets to Eastern Europe, to counter Russia's growing presence. 

Vladimir Putin has placed more than 100,000 troops at the Ukrainian border, and last week Blinken warned that Russia had the capability to double that number in short order. 

The drills will take place 150 miles from Ireland's south west coast, and comes amid the build-up of troops near the border with Ukraine amid fears of a war in Europe

To bolster deterrence, Denmark is sending a frigate to the Baltic Sea and is ready to dispatch four F-16 fighter jets to Lithuania. Spain is deploying ships to join NATO naval forces and is considering sending four F-16 fighter jets to Lithuania. 

France has said it is willing to send troops to Romania and the Netherlands is planning to send two F-35 fighters to Bulgaria in April.   

NATO's announcement came after reports that Biden was weighing sending as many as 50,000 troops to the region if the security situation were to deteriorate, backed up by fresh deployments of ship and aircraft.  

Since late December, the Air Force has been regularly flying RC-135 Rivet Joint electronic-eavesdropping planes over Ukraine in order to listen in on Russian ground commanders' communications, the Times reported. The Air Force is also operating ground-surveillance flights withE-8 JSTARS to track Russian troop buildup at Ukraine's border.

The spy plane mission is meant to find any indications that Russia is considering deploying nuclear weapons to the border with Ukraine, a potential of which Russian officials already warned.

On Sunday, Ukraine's defense minister praised the arrival of a second shipment of military aide from the U.S. 

'The second bird in Kyiv!' tweeted Oleksii Reznikov. 'More than 80 tons of weapons to strengthen Ukraine's defense capabilities from our friends in the USA! And this is not the end.'

On a conference call with reporters Sunday evening, a senior State Department official warned that that 'military action by Russia could come at any time' and urged Americans who wished to leave Ukraine to do so soon.