Iran on Thursday rejected President Donald Trump’s ceasefire plan as it launched another wave of attacks on U.S. ally Israel and on other states in the Gulf region. 

One of the Iranian drone strikes hit a fuel tank at Kuwait International Airport, sparking a fire and delaying multiple flights and rerouting incoming traffic.

Abbas Araghchi, Iran’s minister of foreign affairs, said in a televised interview that, despite U.S. claims that negotiations were under way, the country had no plans to negotiate with U.S. officials. 

Trump, meanwhile, threatened to “unleash hell” on Iran if the ruling regime there does not agree to ceasefire terms.

Iran’s rejection of Trump’s plan comes amid growing pressure, including new Israeli airstrikes on Tehran and an increase in the U.S. deployment of marines and paratroopers in the region.