President Bush Tuesday spoke for the first time with the new Palestinian Prime Minister Mahmoud Abbas. Mr. Bush also telephoned Israeli Prime Minister Ariel Sharon to discuss a Middle East peace plan threatened by renewed violence.

In his call with the new Palestinian Prime Minister, White House spokesman Ari Fleischer says President Bush reiterated the "absolute need" of all parties to fight terrorism.

"The president stressed the need for all parties to take concrete steps and called for cooperative efforts between all Arab parties and Israel to create the conditions for peace and security in the Middle East," he said.

The president's telephone diplomacy comes as another wave of suicide bombings and attacks by Israeli security forces followed the introduction of a so-called "road map" for Middle East peace.

That plan was drawn up by the United States, the European Union, Russia, and the United Nations. It lays out a timeline for power sharing toward the creation of a separate Palestinian state by 2005.

Prime Minister Abbas, who is also known as Abu Mazen, generally accepts the "road map." Prime Minister Sharon has expressed reservations about parts of the plan, including a freeze on Israeli settlements.

Mr. Sharon was to have met with President Bush at the White House Tuesday but postponed his trip because of the recent violence. Mr. Fleischer says the president called the Israeli leader to offer his condolences and discuss the need to continue pursuing peace.

"The president talked about the importance of remaining committed to the peace process in the Middle East, to working forward on the 'road map.' The president informed the prime minister of his call with Abu Mazen and told the prime minister that he believes Abu Mazen is a reformer who will work for peace," he said.

Mr. Fleischer says the president believes the new Palestinian Prime Minister understands that the future success of the Palestinian people depends on attacking those who Mr. Fleischer says "violently seek to derail" the peace process.

He says Mr. Abbas told the president that he is committed to reforming the Palestinian Authority and ending all acts of terrorism.

Tuesday's telephone call by the president comes after years of shunning long-time Palestinian leader Yasser Arafat who Mr. Bush says is not doing enough to fight terrorism.

The president refused to release the "road map" until Prime Minister Abbas and his cabinet were confirmed by the Palestinian Authority. Mr. Fleischer says the president's intervention helped push the peace process forward.

"I think it is absolutely fair to say that if it hadn't been for the president's personal involvement, there would not be a reformist-minded Palestinian prime minister today. There would still be a terrorist-minded leader of the Palestinian people," he said.

Mr. Fleischer says the president understands that Middle East peace will take time and believes the appointment of Mr. Abbas is "a very helpful change."