Israel opened a border crossing with the Hamas-controlled Gaza Strip on Monday for the first time in two weeks, allowing in a limited amount of humanitarian aid.

The move came ahead of talks in Jerusalem between outgoing Israeli Prime Minister Ehud Olmert and Palestinian President Mahmoud Abbas, who termed Israel's tightened blockade of the Gaza Strip a "war crime."

Israeli Defense Ministry spokesman Peter Lerner said approximately 30 truckloads of goods entered the Gaza Strip, including meat and powdered milk for the United Nations Relief and Works Agency (UNRWA).

"It will last a matter of days. But then what?" UNRWA spokesman Christopher Gunness said of the limited supplies.

Israeli officials said future aid shipments hinged on keeping a lid on border violence which has disrupted a 5-month-old truce, due to expire in December, along the Israel-Gaza frontier.

Israel had not allowed UNRWA and other agencies to bring in supplies since November 4, when its troops raided the impoverished coastal enclave to destroy what the army described as a tunnel built by militants to kidnap Israeli soldiers.

Over the last two weeks of cross-border fighting, more than a dozen Palestinian militants have been killed.

Hamas and other groups have responded with rocket salvoes -- including several on Monday. Olmert has described the rocket attacks, which have caused few injuries and little damage, as intolerable.

UNRWA cautioned last week it had run out of food supplies for 750,000 Palestinians in the Gaza Strip because Israel had blocked trucks from entering the territory.

Short of fuel, Gaza's sole power plant has also shut down, resulting in blackouts. No fuel was allowed in on Monday.

Both Israel and Hamas have sent signals they want to restore the Egyptian-brokered ceasefire, which went into effect on June 19.

It calls on Hamas to halt rocket fire and other attacks against the Jewish state. It also demands Israel gradually ease the blockade it tightened on the Gaza Strip more than a year ago after Hamas Islamists routed Abbas's secular Fatah forces.