The Palestinian Authority (search) on Sunday outlawed groups that espouse violence, moving to meet a key Israeli demand for action against militants and boosting a U.S.-backed peace plan.

The decree -- which came as Israeli Prime Minister Ariel Sharon (search) and Palestinian premier Mahmoud Abbas (search) met in Jerusalem -- is identical to one issued in 1998 but effectively rendered invalid during 33 months of violence that followed the collapse of American peace efforts.

In violence late Sunday, a Palestinian was killed while setting off a bomb aimed at an Israeli army vehicle near Jenin in the West Bank, the military said. No one else was hurt.

Sharon and Abbas met for two hours at the Israeli leader's official residence just days before twin summits in Washington between each leader and President Bush. Talks centered on Israel's demand the Palestinians disarm militants, and Abbas' demand for the release of thousands of Palestinians in Israeli jails.

No bold steps came out of the meeting. Sharon's office said afterward that he had pledged to consider Palestinian requests for additional prisoner releases, further Israeli withdrawals from Palestinian towns and the dismantling of Israeli roadblocks in the West Bank and Gaza.

Palestinian lawmaker Saeb Erekat said the delegation called the meeting "a disappointment" because action was delayed until after the meetings in Washington. Abbas will hold White House talk with Bush on July 25; Sharon meets him July 29.

The violence that has wracked the Mideast since September 2000 has dropped considerably since Palestinian militant groups declared cease-fires June 29. Islamic Jihad and Hamas declared a three-month truce; Arafat's Fatah movement called a six-month one.

But disagreements have stalled progress on the "road map" peace plan, which calls for ending violence and creating a Palestinian state by 2005.

In an effort to satisfy Israel, the decree issued Sunday by Palestinian leader Yasser Arafat bans "incitement that encourages the use of violence that harms the relations with foreign countries" and says violators would be judged according to Palestinian law.

In language that seems directed at militant groups, it also bans "illegal organizations that encourage violence and arouse the public to bring about change through force" and "incitement that encourages the violation of the agreements signed by the PLO and foreign countries."

The Palestinian news agency Wafa, which carried a text of the decree, said it was issued by Arafat to reaffirm the 1998 ban. The move follows a Palestinian statement Saturday pledging to restore law and order in the Gaza Strip.

The Israeli statement after the Sharon-Abbas meeting did not mention the decree, but repeated the demand for more action against militants, who have killed hundreds of Israelis over the past three years.

"The prime minister told his counterpart that the Palestinian Authority must act immediately and in a clear-cut way to dismantle the terror organizations," the statement said, setting such action as a condition for further Israeli moves.

Palestinian Information Minister Nabil Amr, speaking in Ramallah, appealed to the U.S. government for help in winning Israeli implementation of the plan.

"We need all the support from our friends the Americans," Amr said.

Hopes on the Palestinian side increased in recent days that Israel was growing more willing to consider releasing more of its estimated 7,700 Palestinian prisoners. Israel has agreed to free several hundred but so far resisted demands for a mass release.

Israeli officials also had angered Palestinians by ruling out releasing members of the Islamic militant groups Hamas and Islamic Jihad. But on Sunday, Cabinet minister Gideon Ezra said it would be possible to free members of those groups not implicated in deadly attacks.

The Israeli statement said a committee dealing with the releases would meet Wednesday, but added that releasing Islamic militants would not be considered until Sharon returns from Washington.

While the release of prisoners is not spelled out as an Israeli obligation in the road map, the Palestinians have made it a major issue. Palestinian security chief Mohammed Dahlan said Sunday the releases were "at the top of our agenda."

"Until now, they're talking about only 400 prisoners. The Israelis right now can release 3,000 Palestinian prisoners without any serious security issues," he said.

Some 1,500 people demonstrated in Gaza City, calling for the release of all Palestinians held by Israel. Islamic Jihad spokesman Mohammed al-Hindi warned there would be "no peace and security" unless all prisoners were freed.

Sharon aide Raanan Gissin said the Israelis rejected a Palestinian appeal to allow freedom of movement for Arafat. Israel's position has been that he can leave the Ramallah compound where he has been for more than a year, but he might not be allowed to return.

Gissin reiterated Israel's position that Arafat is trying to ruin peace efforts. "We want to be very cautious in the steps that we make," he said.

The slow movement on the peace plan gives more importance to the meetings in Washington, said Ali Jerbawi, political scientist at Beir Zeit University on the West Bank.

"If the Americans can pressure the Israelis into delivering, I think that might save the road map," he said. "If the Americans cannot deliver the Israelis, then I think that the road map is doomed."