Famine is quite possibly present in parts of the northern Gaza Strip, a senior US state department official said on Friday, adding that an obstacle to getting more aid to Palestinians was a scarcity of trucks in the enclave under Israeli siege.

The UN has warned of a looming famine and complained of obstacles to getting aid in and distributing it throughout Gaza. The US also says famine is imminent, but the official on Friday told Reuters it might already be present.

“While we can say with confidence that famine is a significant risk in the south and center but not present, in the north it is both a risk and quite possibly is present in at least some areas,” the official said on condition of anonymity.

The UN-backed global authority on food security warned earlier this month that famine was likely to occur by May in northern Gaza and could spread across the enclave of 2.3 million people by July.

UN spokesman Stephane Dujarric on Wednesday described “tremendous challenges” to distributing aid, including a “lack of security, lack of cooperation with the Israeli authorities, lack of insufficient number of trucks, not enough fuel.”

Israeli officials say they have increased aid access to Gaza.