US Secretary of State Antony Blinken has defended a decision to pause a delivery of 3,500 bombs to Israel over concerns they could be used in the Gazan city of Rafah, saying Israel lacked a “credible plan” to protect some 1.4 million civilians sheltering there, Reuters reports.

Speaking on ABC News programme ‘This Week’, Blinken said that President Joe Biden remains determined to help Israel defend itself and that the shipment of 3,500 2,000-pound and 500-pound bombs was the only US weapons package being withheld.

That could change, he said, if Israel launches a full-scale attack on Rafah, which Israel says it plans to invade to root out fighters of the ruling Hamas fighter group.

Biden has made clear to Israel that if it “launches this major military operation to Rafah, then there are certain systems that we’re not going to be supporting and supplying for that operation,” said Blinken.

“We have real concerns about the way they’re used,” he continued. Israel needs to “have a clear, credible plan to protect civilians, which we haven’t seen.”