Israel has been repeatedly accused of blocking or obstructing aid deliveries to northern Gaza, though humanitarian organisations have said the number of lorries being let in has increased since May.
Aid convoys carrying vital have also reportedly been fired upon by Israeli forces, while others have been looted by desperate crowds and criminal gangs.
World Central Kitchen, a US-based nonprofit group, resumed operations on Monday after seven of its aid workers were killed by an Israeli airstrike in April. It has distributed over 43 million meals across Gaza.
Israel has denied such claims. It instead blamed the UN and other international organisations for logistical problems and delays.