"If this impact [from sanctions] grows, you may see, there is a lot of mobility there, and the mobility is not just between Afghanistan and Iran, mobility is also onward. We have seen refugees that have spent a lot of time in Iran moving on to Turkey, and then to Europe," Grandi said.
The official added that the United Nations had alerted European countries about this possibility.
"We have alerted European countries, that since they are very much involved in the whole political discussion around sanctions, they should keep that factor in mind as well," he said.
Lowcock stated that US sanctions had already had an impact on the value of Iran’s currency, which has taken a toll on refugees.
"There are sanctions, US sanctions now and that pressure is already visible. The rial, the national currency is precipitating in value; purchasing power for many people is highly reduced. This affects everybody. This affects also the refugees," Grandi said.