The Pentagon has confirmed they will send 750 soldiers to the Middle East as soon as possible.

The deployment is in direct response to an attack by pro-Iranian protesters on the US embassy in Iraq.

US Defense Secretary Mark Esper said in a statement: "This deployment is an appropriate and precautionary action taken in response to increased threat levels against US personnel and facilities, such as we witnessed in Baghdad today."

Esper added: "The United States will protect our people and interests anywhere they are found around the world."

The 750 soldiers who will be deployed immediately will join the 14,000 US military personnel who are already stationed in the Gulf region. Esper added that the full 82nd Airborne quick-deployment brigade could send about 4,000 soldiers in all.

US President Donal Trump tweeted that "They will pay a very BIG PRICE!" referring to Iran. He also thanked Iraqi officials for their help in dealing with the attack.  

Iran's religious leader Khamenei warns US

Iran's religious leader Ali Khamenei condemned the US bombing of pro-Iranian Shiite militias in Iraq and said: "This character [Trump] once again blamed Iran for the attacks."

Addressing Trump directly, Khamenei said: "You can't do anything. If you were reasonable, which you are not, you would see nations hate you for crimes you have committed in Iraq and elsewhere... If Iran decides to clash with a country, it does so openly. If someone threatens the interests of our nation, we will respond without hesitation."