KARNI CROSSING, Gaza Strip — Secretary of State Rice left Israel yesterday after winning only lukewarm support for a plan to ease the humanitarian crisis in Gaza by improving access for commercial trucks.

As the Ms. Rice flew on to Baghdad for surprise talks with the Iraqi government, Israel said it agreed only in principle to her plan and expected more time to consider the details.

“It is a step forward inasmuch as Israel accepts the concept of the plan, but we have not seen the details yet, and nothing will change until all the details are agreed,” a government spokesman, Mark Regev, said.

Blockages at the Karni Crossing lie behind many of Gaza’s current problems, as it is the only large-scale access point for imports and exports.

An earlier agreement, also brokered by Ms. Rice last year, envisaged scores of trucks coming and going each day, but this proved an illusion, as Israel has routinely closed the crossing for what it said were security reasons.

Under the $20.7 million scheme proposed by America, Israel would open the Karni Crossing fully because international observers would be deployed alongside an increased Palestinian Arab security presence.

To get around distrust of the Hamas government, the scheme envisages only Fatah supporters loyal to the Palestinian Arab president, Mahmoud Abbas, being used to man security at the crossing.

In Baghdad, Prime Minister Maliki of Iraq said a political solution must be found that would lead the sectarian militias to “dissolve themselves” and end the violence. But Ms. Rice said Iraq’s embattled leaders “don’t have time for endless debate of these issues.”

“They have really got to move forward,” she said.