U.S. Secretary of State Antony Blinken pledged on a Middle East mission on Tuesday that Washington would rally support to rebuild Gaza as part of efforts to bolster a ceasefire between its Hamas Islamist rulers and Israel.

He however made clear that the United States intended to ensure that Hamas, which it regards as a terrorist organisation, did not benefit from the humanitarian aid – a potentially difficult task in an enclave over which it has a strong grip.

Blinken began his regional visit in Jerusalem, where he held talks with Prime Minister Benjamin Netanyahu. The Israeli leader, speaking to reporters with the top U.S. diplomat at his side, threatened a “very powerful response” if Hamas renewed cross-border rocket strikes.

The truce, brokered by Egypt and coordinated with the United States, began on Friday after 11 days of the worst fighting between Palestinian militants and Israel in years. Now in its fifth day, it has been holding.

“We know that to prevent a return to violence we have to use the space created to address a larger set of underlying issues and challenges,” Blinken said.

“And that begins with tackling the grave humanitarian situation in Gaza and starting to rebuild.”

The United States, he said, would work to rally international support around that effort and make its own “significant contributions”, to be announced later in the day.

“We will work with our partners, closely with all to ensure that Hamas does not benefit from the reconstruction assistance,” Blinken said about the group.