President Bush has called Israeli Prime Minister Ariel Sharon with a strong message: halt your military offensive in the West Bank now. On the eve of Secretary of State Colin Powell's trip to the region, the president urged the prime minister to act.

At a joint press conference Saturday near his Texas ranch with visiting British Prime Minister Tony Blair, Mr. Bush's frustration with Israel was showing. Two days after he first called for a withdrawal, Israeli forces were still on the move. The president said they should halt the incursion and pull out of occupied cities without delay.

"I don't expect them to ignore," he said. "I expect them to heed the call: heed the call from their friends, the United States and heed the call from their friends, the people of Great Britain and the leadership of Great Britain."

Three hours later, Mr. Bush called Ariel Sharon to reinforce that message.

During the 20-minute conversation, the president expressed his deep concern about events in the region. He said Israel must diffuse the situation so diplomacy can succeed.

In Israel, the prime minister's office said Mr. Sharon told President Bush that he would expedite the offensive in the West Bank. There was no indication of a timetable.

When asked about the comments, a Bush administration official said the president wants to see action - not just words from Ariel Sharon. The official said President Bush told the prime minister Israel needs to make progress now.