JERUSALEM (AFP) - Israel is seeking US guarantees to back up an emerging Egyptian proposal to how to stem arm smuggling into Gaza in order to end its war on Hamas, a senior Israeli official told AFP. "The diplomatic efforts are focused on reaching a viable arrangement that will prevent weapons from reaching Gaza from the Sinai peninula," he said on condition of anonymity, referring to talks ongoing in Cairo. Israel is now seeking US guarantees to back any deal reached, he said. "We are working closely with the United States in order to obtain from them guarantees towards us to halt arms smuggling," he said. The Jewish state has repeatedly made clear it will not halt its offensive until an international mechanism is created that no weapons enter Gaza via the hundreds of tunnels that snake into the Palestinian territory from Egypt. The official said that under any truce deal, Israel intends to reserve its right to respond militarily to rockets fired from Gaza or to any smuggling activity. "The diplomatic outcome must allow us on the one hand to freely act against militancy in Gaza and on the other hand it must not tie our hands in any way," he said. "We do not want any deal with Hamas that will legitimise the terror organisation." Egyptian President Hosni Mubarak is spearheading US-backed efforts to secure a ceasefire in Israel's 16-day-old war on Hamas which rules the Gaza Strip. Last week he presented a proposal that called for an immediate truce, opening Gaza's border crossings, preventing arms smuggling and a call for Palestinians to resume reconciliation talks. The United States in 2008 deployed engineering experts along the border to assist Egyptian authorities to locate and destroy the tunnels, though the experts withdrew after the start of the Israeli offensive. Washington has also promised Egypt 33 million dollars to buy new technology to uncover tunnels.