A top Hamas leader defiantly vowed to win "victory" against Israel on Monday as Islamist fighters battled to prevent Israeli troops from taking over their Gaza stronghold.

"Victory is coming, God willing," Zahar said in his first television address since the launch of Israel's offensive against Hamas on 27 December.

Zahar insisted the group's armed wing, the Ezzedine Al-Qassam Brigades, "has given the most beautiful performances during its confrontation with the army that the world thought invincible".

"We will defeat it, God willing."

The statement came as a Hamas delegation was to travel to Egypt for talks on ending the offensive that Israel unleashed in response to persistent rocket fire by Gaza militants.

Dressed entirely in black, his face sombre and his tone grim, Zahar read out a statement in what appeared to be a hastily prepared recording, sitting in an empty room.

'Free all of Palestine'

"The painful tests of today will help us realise our national aspirations of tomorrow," he said, adding that Hamas was not renouncing its aim to "free all of Palestine".

The hardliner, widely considered to be the most influential Hamas leader in the Gaza Strip, lashed out against the United Nations and the West, accusing the international community of doing nothing to prevent the devastating Israeli offensive.

He called for an "end to the aggression, the withdrawal of (Israeli) forces and the lifting of the blockade" that Israel imposed on Gaza after Hamas seized control of the territory in June 2007.

"If that happens, we will be ready to discuss anything that can be in the interest of the Palestinian people," he said.

A delegation of senior Hamas officials was to leave for Egypt for talks on how to end the war in the tiny territory sandwiched between Israel and Egypt.

"We have received an invitation from Egypt and we're going to Cairo to listen to Egyptian officials and discuss with them suspended issues, notably the (permanent) reopening of the Rafah crossing between Egypt and the Gaza Strip," said Hamas politburo member Ossama Hemdan.

The delegation heading to Cairo will include two members of Hamas's political leadership, Emad al-Alami and Mohammed Nasr, Hemdan said.

"We want an immediate end to Israeli aggression and the lifting of the blockade and we will listen to Egyptian proposals," he added.

Israeli Defence Minister Ehud Barak said the army had dealt a heavy blow to Hamas.

A senior Israeli minister said on Sunday that the Islamists may be seeking "a respectable" way out of the conflict having underestimated the scope of the offensive.

"The intelligence reports that we've received today in the Israeli Cabinet are that the Hamas is looking for a respectable way of finding a way to get out of this situation," Welfare Minister Isaac Herzog told CNN television, adding that the Islamists were under "huge pressure".

AFP