Great Britain also issued security alert for its personnel in Iraq. The threat leveal was raised for UK troops and diplomats in Kuwait, Qatar, and Saudi Arabia as well.
Earlier this week the US State Department ordered the departure of "non-emergency government employees" from Baghdad and Erbil after US Central Command spokesman Bill Urban that the US-led coalition was on high alert because it saw credible threats to American forces in Iraq.
However, British Maj. Gen. Christopher Ghika, who is a deputy commander of the coalition forces, stated that the threat level by Iranian-backed groups against the troops in Iraq and Syria has not risen.
The news comes after the US increased its military presence in the Middle East amid growing tensions with Tehran, sending an aircraft carrier strike group to the Persian Gulf.
According to White House National Security Adviser John Bolton, Washington is fully prepared to "respond to any attack, whether by proxy, the Islamic Revolutionary Guard Corps, or regular Iranian forces".
In the meantime, the Islamic Republic has suspended certain obligations under the 2015 nuclear deal, giving five remaining signatories — France, the UK, Russia, China, and Germany — a 60-day deadline to take measures towards ensuring the country's interests amid US sanctions.