According to the Ukrainian National Security and Defense Council, there were 177 people on board: 168 passengers and nine crew members. The plane had taken off from Imam Khomeini International Airport and is believed to have crashed due to mechanical problems, reports said.
His office said he had cut his visit to Oman short and was returning to Kyiv because of the crash.
This is the first fatal crash for Ukraine Airlines since its founding in 1992. A video aired by the state media broadcaster appeared to show the plane already on fire, falling from the sky. The plane was carrying 180 passengers and crew.
Iranian state TV reported that officials got word of the crash just before 6:30 a.m., and it involved a Boeing 737.
Earlier the Federal Aviation Administration in the U.S. has said it was issuing flight restrictions that prohibited civil operators flying over airspace in the region.
Iran is in the news after they launched more than a dozen ballistic missiles at an Iraqi military base housing United States troops several hours before the crash in response to the U.S. operation that killed Iranian general Qasem Soleimani last week.
Boeing has been under increased scrutiny since two Boeing 737 Max planes were involved in two fatal crashes that killed a total of 346 people.
Iran launched a series of ballistic missiles this morning, which were targeted at USA air bases in Iraq.