Israeli ultranationalist Finance Minister Bezalel Smotrich is blocking a U.S.-funded flour shipment to Gaza because its recipient is the UN Relief and Works Agency (UNRWA), two Israeli and U.S. officials told Axios.

Why it matters: U.S. officials said this is a violation of a commitment Benjamin Netanyahu personally made to President Biden several weeks ago and another reason for the the U.S. leader is frustrated with the Israeli prime minister.

Driving the news: The highest levels of the Biden administration brought up the possibility of the flour shipment more than a month ago.

• The Israeli war and security cabinets approved the delivery of the flour from the port of Ashdod in southern Israel to Gaza through the Kerem Shalom crossing, Israeli officials said.
• Biden and Secretary of State Tony Blinken have already publicly thanked the Israeli government for allowing the flour shipment to go through.

Yes, but: The shipment has been stuck at the Ashdod port for weeks. Israeli and U.S. officials blame Smotrich, who is in charge of the Israeli customs service.

• According to U.S. and Israeli officials, Smotrich blocked the transfer of the flour after he was notified that it was destined for the UN Relief and UNRWA, the primary aid group in Gaza. He ordered the Israeli customs service not to release the shipment as long as UNRWA is the recipient.
• UNRWA has been under international scrutiny recently over Israeli accusations that 12 of its employees took an active part in the Oct. 7 attacks. Several countries, including the U.S., have temporarily suspended their aid to UNRWA, pending the results of an independent investigation ordered by the UN.
• Smotrich's office and the White House didn't immediately respond.

The big picture: Gaza's entire population — more than 2.2 million people — is facing crisis or worse levels of hunger, with the risk of famine increasing every day, a UN-backed body said in a report late last year.

• About half of Gaza's population is facing emergency levels of food insecurity, the report found.

What to watch: Israeli officials said they are now trying to reroute the shipment so that it would enter Gaza through the World Food Program in order for Smotrich to release the hold.

Go deeper: Biden says U.S. will do "everything possible" to get new Gaza hostage deal