ERBIL, Kurdistan Region of Iraq - The US State Department on Wednesday held Hamas responsible for the resumption of Israel’s deadly strikes on Gaza, citing the Palestinian group’s reluctance to accept a proposal to extend the first phase of the truce.

Israel on Tuesday launched a series of deadly airstrikes on the Gaza Strip, on a scale not seen since a ceasefire with Hamas began on January 19. Gaza's civil defense agency on Wednesday said that at least 436 people have been killed in the recent strikes.

“Hamas bears total responsibility for the war, and for the resumption of hostilities,” US State Department spokesperson Tammy Bruce told The New Region on Wednesday.

“Every death would have and could have been avoided had Hamas accepted the ‘bridge’ proposal that [Special Envoy Steve] Witkoff offered last Wednesday,” she added.

The first stage of the three-phase ceasefire between Israel and Hamas expired on March 1. Witkoff, Washington’s envoy to the Middle East, last week proposed extending the first phase until mid-April which would include another prisoner-hostage swap.

Hamas instead has insisted on proceeding with the initial agreement, the second phase of which was meant to establish a lasting ceasefire and an Israeli withdrawal from Gaza.

“Hamas is delaying the compelling deal in front of us and forcing Palestinians to suffer the consequences,” said Bruce, reiterating Washington’s support for Israel.

Israeli Prime Minister Benjamin Netanyahu warned late Tuesday that the strikes were “only the beginning” and that future negotiations with Hamas “will take place only under fire.”

Netanyahu attributed the renewed campaign on Gaza to “Hamas' repeated refusal to release” the remaining hostages.

A total of 59 Israeli hostages are still held by Hamas in Gaza, of which 24 are believed to be alive.