A US aircraft carrier strike group was deployed to the Middle East amid rising tensions with Iran (Picture: US Department of Defense).
Tensions between the United States and Iran have arguably been developing for some time.
The latest incident between the two nations is a dispute over a US drone shot down by Iran's Revolutionary Guard.
The Americans say it was flying in international airspace, while the Revolutionary Guard says it was in Iranian skies.
Parts of the Middle East are of strategic importance to the United States.
The USS Abraham Lincoln carrier group is currently located in the Arabian Sea, four B-52 Strategic Bombers are at Al-Udeid Air Base in Qatar, four F-35A Lightning II jets are based in Abu Dhabi and US Patriot air defence missiles are positioned across the United Arab Emirates.
Tensions have escalated as Iran appears poised to break the 2015 nuclear deal with world powers.
President Donald Trump pulled the US out of the deal last year, labelling it "horrible" and "one-sided" which left them to be "held hostage to nuclear blackmail".
But President Trump did also say he was "willing" to make a new deal, although recent developments may mean that is now unlikely.
The deal, reached by global powers including the UK, US and China, saw Iran agree to limit its enrichment of uranium in exchange for the lifting of crippling sanctions.
But fast forward to 2019 and Iran claims it has quadrupled its production of low-enriched uranium.
US sanctions have cut off opportunities for Iran to trade its excess uranium and heavy water abroad.
Iran says the sanctions have crippled their economy and have called on Europe to help and without any, they say they may be pushed to break the nuclear deal - something President Hassan Rouhani says he does not want to do.
Last year, President Trump announced plans to withdraw troops from the Middle East.
He announced all troops in Syria would return to the US, while there would also be a partial withdrawal in Afghanistan.
But he said soldiers will be staying in Iraq to "watch" Iran, calling the country a "real problem".
Since then, the US has continued to strengthen its military presence in the region.
In May, the US deployed aircraft carrier USS Abraham Lincoln to the Middle East to counter what they described as a growing threat from Iran.
No exact details were released of the threat posed by Iran but the Pentagon said there were signs of heightened Iran readiness to conduct offensive military operations.
An additional Navy ship and missile defence system were also deployed to join the strike group which included B-52 Bombers.
In the same month, the US also announced plans to send additional troops to the region, something Iran's foreign minister slammed as "extremely dangerous" to "international peace and security".
More recently, incidents involving oil tankers have worsened the US-Iran relationship.
First, Saudi Arabia said two of its oil tankers had been sabotaged off the coast of the United Arab Emirates (UAE).
Four ships in total were damaged in the attack.
Saudi Arabia said one ship was carrying Saudi oil which was heading to the US.
The US accused Iran of being behind the attack but Tehran denied all allegations - further exacerbating the already strained relations.
US National Security Adviser John Bolton said "naval mines almost certainly" from Iran were to blame for the damage.
But a spokesman from Iran's foreign ministry said Mr Botlon's claim was "ludicrous" and called him a "warmonger".
Weeks later, UAE told the UN Security Council a "state actor" was most likely behind the attack.
Two more oil tankers have since reportedly been attacked, this time in the Gulf of Oman.
The US Navy's USS Bainbridge rushed to provide assistance to the incident which happened 25 miles off the Iranian coast.
The US responded by releasing a video and then images which it says provide further evidence that Iran is to blame for the attacks on two tankers and also committing to send 1,000 extra troops to the Middle East.
Iran has denied any involvement in the attacks, with President Hassan Rouhani stating his country is not seeking to "wage war with any nation".
On Thursday, a US drone was shot down, with American and Iran disagreeing over whose airspace the craft was flying through.