Such Israeli action would likely torpedo a six-month truce in the Gaza Strip and could threaten US efforts to revive the Israeli-Palestinian peace process.

Meanwhile, Israel's Prime Minister Ehud Olmert will travel to Jordan on May 15 to meet with King Abdullah, the prime minister's office said Tuesday.

Olmert and the king will meet in the ancient city of Petra on the sidelines of an annual gathering in Jordan of Nobel Prize laureates.

In a setback to US efforts on the peace process, the State Department announced Monday that US Secretary of State Condoleezza Rice cancelled an upcoming visit to the region, citing the uncertain political situation after an Israeli commission found Olmert's government mishandled last year's war in Lebanon.

The Gaza cease-fire has sharply reduced fighting, but militants have continued to fire homemade rockets into southern Israel. The rocket fire has spiked in recent days, including two more projectiles launched Tuesday. No injuries were reported in Tuesday's attack, the army said.

On Monday, Israel carried out a rare airstrike in Gaza, attacking a car carrying rockets near the Israeli border, and Prime Minister Ehud Olmert warned he was losing patience with the rocket barrages.

The military's plan for a 300-yard-deep zone inside Gaza is one of several options Israel is considering to counter the rocket fire, the military officials said on condition of anonymity since they were not allowed to discuss the plan with the media.

Ghazi Hamad, spokesman for Palestinian Prime Minister Ismail Haniyeh, called the proposal a "dangerous idea."

"It will cause more confrontations. It won't provide stability," he said.

Military commanders have presented the plan to Olmert's Cabinet but it has not yet been approved, the officials said. The plan will be debated by senior Cabinet ministers next week, Haaretz reported Tuesday.

Israel periodically carries out "pinpoint" operations on the edges of Gaza to halt rocket launchings. The military's plan calls for a greater presence that would be constant in some places, the officials said.

The plan also calls for an increase in attacks on rocket launchers, including airstrikes on high-ranking militants who oversee the firings, the officials said. Olmert has already agreed to slightly expand the area in the Gaza Strip in which the army can operate, Haaretz said.

Israel has grown increasingly concerned by arms smuggling into the Gaza Strip and the rocket fire. Senior military officials have been pushing for approval of a large land offensive in the Gaza Strip to stop the rocket fire, but other security chiefs are opposed to such a complicated operation in the densely-populated coastal area that could exact many Israeli troop casualties.