Israeli envoy Amos Gilad was in Cairo on Thursday for Egyptian-mediated talks on clinching a lasting truce with Hamas expected to focus on stemming arms smuggling across the porous Gaza-Egypt border.

Gilad arrived "for a short visit to meet with senior officials to discuss consolidating the ceasefire in Gaza," Egypt's state MENA news agency said.

Egypt invited Hamas to Cairo for separate talks on Thursday on shoring up the fragile ceasefire that took effect on January 18, but the Islamists will only send a delegation to Cairo on Sunday, the foreign ministry said.

Hamas postponed their visit to allow for more consultations between Egypt and Israel on ways of consolidating the ceasefire "that would be acceptable to both sides," a senior official told MENA.

During the 22-day Israeli blitz on Gaza which killed 1,330 Palestinians and left 13 Israelis dead, Egyptian intelligence chief Omar Suleiman met separately with Israeli and Hamas officials to negotiate a ceasefire based on a three-point proposal by President Hosni Mubarak.

The plan unveiled on January 6 calls for an immediate ceasefire, opening up the isolated territory's crossing points and a resumption of Palestinian reconciliation talks.

But the thorniest goal for Israel will be to find a permanent solution to the root causes of Israel's blitz of Gaza, which includes arms smuggling into Gaza.

Thursday's talks come amid fresh warnings from Israel that the military could launch renewed attacks against the network of tunnels it says are used to smuggle weapons under the Rafah border between Gaza and Egypt.

"For the tunnels, nothing will be as it was before," Israeli Foreign Minister Tzipi Livni told public radio on Thursday. "Things must be clear -- Israel reserves the right to react militarily against the tunnels once and for all."

On the Egyptian border, hundreds of Palestinian smugglers have resumed work on the tunnels, an AFP journalist reported.

Israel launched Operation Cast Lead on December 27 to halt rocket attacks from Gaza which it says is awash with weapons, some of which are smuggled into the territory through the Rafah border -- the only Gaza crossing that bypasses Israel.

Cairo hopes to reach a deal to secure the border and that in return Israel would lift the punishing blockade it imposed on Gaza after Hamas took over the territory from its rival Fatah in June 2007.

Israel said that it stopped its deadly offensive on Sunday only after securing guarantees on weapons smuggling from Egypt and the United States.

Israel and the United States last week signed an agreement on clamping down on arms smuggling but Egypt has said it is not bound by the deal.

Key European states Britain, France and Germany have also offered to help prevent arms smuggling into the Gaza Strip, with London saying it was ready to provide naval support.

Livni was in Brussels on Thursday pressing the Jewish state's concerns about weapons smuggling, with the European Union in turn seeking assurances that humanitarian aid would be allowed into the war-torn Gaza Strip.

The EU has a team of almost 30 monitors at the Rafah terminal but it has rarely been unable to work as Israel has often kept the crossing closed, citing security concerns. Diplomats said the numbers could be doubled.

But exiled Hamas chief Khaled Meshaal insisted on Wednesday that there were "two more battles" with Israel left to be won.

"We achieved our aims by forcing the enemy to halt its aggression and to withdraw," Meshaal said on Arab satellite television from his base in Damascus.

"But two more battles are left to win: to lift the blockade and open the crossing points (with Gaza), especially at Rafah which is our gateway to the world."