Israeli Prime Minister Benjamin Netanyahu said on Sunday that Israel is ready to "significantly expand" its operation against militants in the Hamas-run Gaza Strip.

"The army is prepared to significantly expand the operation," Netanyahu said at the start of a weekly cabinet meeting. "The soldiers are ready for any activity that could take place."

His remarks came as thousands of Israeli troops gathered along the border, fuelling concerns that the Jewish state was poised to expand its relentless aerial bombing campaign into a ground operation.

Israel's campaign against Gaza rocket operations, which entered its fifth day, is at a crossroads of whether to launch a ground invasion or pursue Egyptian-led truce efforts. Israel has said it is not prepared to enter into a truce without guarantees the rocket fire won't resume.

The fighting is unlikely to end anytime soon, said Ye Hailin, an expert on Middle East studies at the Chinese Academy of Social Sciences.

"What Israel really wants is a strategic deterrence in the region and forcing relevant countries, including Egypt and the United States, to choose a clear side," Ye said.

Israeli strikes hit two media centers in the Gaza Strip on Sunday. Palestinian militants meanwhile fired at least one more long-range rocket at Tel Aviv.

Some 56 Palestinians, about half of them civilians, including 14 children, have been killed since the Israeli offensive began, Palestinian officials said, and hundreds have been wounded. More than 500 rockets fired from Gaza have hit Israel, killing three civilians and wounding dozens.

Israel's Foreign Minister Avigdor Lieberman said on Sunday that Israel would not negotiate a truce with Hamas as long as rocket fire continues from the Palestinian enclave.

The Israeli army sealed off the main roads around Gaza late on Nov 16 and shortly afterward the cabinet authorized the recruitment of up to 75,000 reservists, and tens of thousands have already been drafted, prompting a flurry of diplomatic efforts to broker a truce to head off any escalation.

Diplomats at the United Nations said Secretary-General Ban Ki-moon was expected to visit Israel and Egypt in the coming week to push for an end to the fighting.

As his security deputies sought to broker a truce with Hamas leaders, Egyptian President Mohamed Mursi said in Cairo that "there are some indications that there is a possibility of a cease-fire soon, but we do not yet have firm guarantees".

Egypt has mediated previous cease-fire deals between Israel and Hamas, the latest of which unraveled with recent violence.

A Palestinian official told Reuters the truce discussions would continue in Cairo on Sunday, saying "there is hope", but that it was too early to say whether the efforts would succeed.

A Beijing-based analyst on Middle East affairs speaking on condition of anonymity said Israel will likely continue airstrikes instead of using ground troops to get more attention from the US.

"Israel is worried over the US' withdrawal from the Middle East as it has shifted to the Asia-Pacific in recent years," the analyst said.

Israel is also trying to affect the Palestinian authority's bid to become a UN observer state, which is expected to be presented on Nov 29, he said.

US President Barack Obama on Sunday defended Israel's right to defend itself against attacks and decide how to respond to rocket fire from the Gaza Strip, saying "no country on earth would tolerate missiles raining down" on its people.

A ground invasion of the Gaza Strip would cause Israel to lose international sympathy and support, William Hague, British foreign secretary warned on Sunday.

Hague told Sky News television it was much more difficult to limit civilian casualties in a ground assault and it would threaten to prolong the conflict.

AFP-AP-Reuters-China Daily