British Airways said on Thursday it is suspending flights between London and Tehran because they are not commercially viable.

The route was reinstated in the wake of a 2015 accord between Western powers and Iran under which most international sanctions on Iran were lifted in return for curbs on the country's nuclear program.

Three months ago however, President Trump withdrew Washington from the deal, blasting it as flawed and reimposing sanctions to choke Iran's economy and force it to renegotiate or change direction.

British Airways, which is owned by Spanish-registered IAG, said its last outbound flight from London to Tehran will be on Sept. 22 and the last inbound flight from Tehran will be on Sept. 23.

"We are suspending our London to Tehran service as the operation is currently not commercially viable," the airline said in a statement.