Iran is struggling to meet domestic petrol demand after a US naval blockade disrupted the country’s ability to import fuel.

Vice President Mohammad Jafar Ghaempanah said on Wednesday that domestic petrol production was not enough to meet the country’s needs, while the blockade had made it impossible to bring in additional supplies.

The shortage has led to long queues at petrol stations in several parts of Iran as the ongoing conflict with the United States puts increasing pressure on the country’s economy.

Iranian authorities are also considering changes to its fuel allocation system. Presidential chief of staff Mohsen Haji-Mirzaei said on Monday that petrol quotas would be reviewed, although he did not explain what changes were being considered.

The conflict between Iran and the United States began on February 28. Iran has since taken control of the strategic Strait of Hormuz, while the US has imposed a naval counter-blockade around Iranian ports.

Ghaempanah also criticised Iran’s heavily subsidised petrol system, saying the current arrangement favours people who own several vehicles while offering fewer benefits to those without cars.

Iran has some of the world’s cheapest petrol prices because of extensive government subsidies. Any attempt to change the pricing or subsidy system, however, remains politically sensitive.