BERLIN — Countries at an international conference yesterday agreed to commit $242 million to strengthen the Palestinian Authority’s police and judicial systems, sending what Germany’s foreign minister called a “clear signal of support” for building a Palestinian Arab state.

The money will go to projects that include police training, building a forensic lab and prisons, installing communications networks, and creation of courthouses.

Organizers had hoped for commitments of $190 million going into the meeting, which brought together officials including the Palestinian Arab prime minister, Salam Fayyad; Secretary of State Rice; the Israeli foreign minister, Tzipi Livni, and the Arab League secretary-general, Amre Moussa.

“The result, I must say, is that a clear signal of support for the building of a Palestinian state was sent from here today,” the conference host, Foreign Minister Frank-Walter Steinmeier of Germany, said.

Officials stressed that improving the civilian security infrastructure of the Palestinian Authority — which controls only the West Bank after last year’s takeover of Gaza by the Islamic militant Hamas — was essential to the creation of a Palestinian Arab state.

“It is not enough to determine the borders of a future Palestinian state,” Mr. Livni said as the conference opened. “When handing over the keys to the Palestinians, we must know that our neighbor is not a failed state or a terror state but a partner in peace.”

The International Middle East envoy, Tony Blair, said upgrading security was essential regardless of whether progress is made toward an Israeli-Palestinian Arab peace deal by the end of the year, a precursor to establishing a Palestinian state.

“It is important in any event that we build the capacity and the capability of the Palestinian Authority,” Mr. Blair said at a news conference.

Not only does it matter to Palestinians Arabs that there is a proper authority for law and order, he said, but having additional security capacity will make it easier to push for an end to Israeli occupation.

Mr. Fayyad welcomed what he called “a strong expression of support” for a Palestinian Arab state and said that “security is the most important service any responsible government must provide to its citizens.” But he also stressed the need for Israel to comply with international demands for a freeze in building Jewish settlements and for a change in Israeli “security behavior.”