The US military carried out multiple airstrikes against facilities in Syria used by Iran-aligned forces on Thursday.
The attack and the retaliation by the US have threatened to disrupt recent efforts in the region to de-escalate the situation.
What we know so far
Earlier on Thursday, a drone suspected to be of Iranian origin struck a facility on a coalition base in Northeast Syria.
A US contractor was killed, another employee was injured, and several US service members were left injured.
The Pentagon said that, according to an intelligence assessment, the unmanned aerial vehicle was of Iranian origin.
"The airstrikes were conducted in response to today's attack as well as a series of recent attacks against coalition forces in Syria by groups affiliated with Iran's Islamic Revolutionary Guards Corps," said US Defense Secretary Lloyd Austin.
Syria and Iran have not yet reacted to the strikes which have come during the holy Muslim fasting month of Ramadan.
Meanwhile, Qatar's state-run news agency reported a call between its Foreign Minister, Khalid Al Attiyah, and US national security advisor Jake Sullivan.
Attiyah reportedly also spoke to the Iranian Foreign Minister Hossein Amirabdollahian.
Recently, Doha has been an interlocutor between Iran and the US over their tensions about Tehran's nuclear program.
A volatile but strategic region
Social media videos on Friday showed explosions in Syria's Deir Ez-Zor, a strategic province, which borders Iraq and contains oil fields.
Iranian-backed militia groups and Syrian forces control the area. In recent months, the region has been hit by suspected Israeli airstrikes that targeted Iranian supply routes.
Iran's paramilitary has allegedly attacked the wider Middle East with bomb-carrying drones.
Recently, Russia began using Iranian drones in its attacks across Ukraine.
Iran has refused to take any responsibility for these attacks. However, Western nations have traced components in the drones back to Tehran.