A senior Republican senator urged the Bush administration Wednesday to take a more active role in seeking peace in the Middle East, saying Secretary of State Colin Powell should not wait until success is assured. 

"The issues are too vital," said Sen. Arlen Specter of Pennsylvania, who serves on the Senate Appropriations subcommittees on defense and foreign operations. "It's nice to go when you've got it all worked out and you can have a triumphant trip, but you can't go to bat and expect to hit a home run every time." ght to make the effort even if it fails." 

Specter, just back from a trip to Jerusalem, said U.S. special envoy Anthony Zinni told him there are plans for a limited number of U.S. monitors to oversee any peacekeeping effort. 

"If it comes to having a U.S. involvement, I think they ought to be armed and they ought to be military, whether you call them monitors or peacekeepers," Specter said. 

With the violence level in Israel and the West Bank rising daily, the State Department is advising American residents of Jerusalem to relocate to safer places and is encouraging dependents of American diplomats in the city to return to the United States. 

A new travel warning issued Tuesday cited a "deteriorating security situation" and repeated previous advice to U.S. citizens not to go to Israel. 

"The potential for further terrorist acts remains high," the department statement said. "The situation in Jerusalem, the West Bank and Gaza remains extremely volatile with continuing terrorist attacks, confrontations and clashes." 

Warnings to stay away from Israel were issued to Americans in December and January. The latest, more pointed, specified Jerusalem as a place Americans should consider leaving and offered government-paid trips home to families of U.S. diplomats and of other American workers at the U.S. consulate in Jerusalem. 

The departure of dependents, which is not mandatory, was based on the general situation and not on any specific threats against Americans, a U.S. official said. 

Israel's economy already is staggering under the destruction caused by terror attacks, the expense of a military buildup and a sharp decline in tourist visits. The new U.S. warning is bound to add to Americans' anxieties about visiting Israel. 

The United States, which like most countries does not recognize Jerusalem as Israel's capital, maintains its embassy in Tel Aviv. The authorized departure of dependents, as the approval is called, does not apply to the embassy. 

Tel Aviv also has suffered bloody attacks, but with less frequency. 

Also Tuesday, the University of California said it was arranging travel back to the United States for 27 students enrolled in programs in Israel and putting its fall 2002 academic program in Israel on hold "in view of the dramatically escalating violence in the Middle East." 

The school said it was joining the universities of Colorado and Washington in recalling students from Israel. The university noted that 28 of its students in Israel previously abandoned their studies there. 

President Bush lamented the Middle East impasse, saying Israel has a right to exist and Palestinians have a right to live in their own state one day. 

"There are those who want to destroy that vision" of a peaceful Middle East, he said at a political fund-raiser in Philadelphia. "There are those who want to murder to make sure that vision never comes to be." 

Powell made another call to Israeli Prime Minister Ariel Sharon on Tuesday, his third since Saturday, and talked also to Prime Minister Ali Abul-Ragheb of Jordan. 

Jafar Hassan, who heads the Jordanian Embassy in Washington, said Israel's actions on the West Bank were having "an extremely negative impact" on relations between Israel and Jordan. 

Also, Hassan said in an interview, Jordan's attempts to steer Israel and the Palestinians into a peace accord have been damaged. 

Abul-Ragheb urged the Bush administration to end Israel's siege on Yasser Arafat's Palestinian Authority headquarters at Ramallah, on the West Bank, and to force Israel to withdraw its troops from Palestinian-held areas, the Jordanian news agency Petra said. 

Egypt's Middle East News agency reported President Hosni Mubarak had sent a "personal and urgent" message to Bush to urge him to "take an immediate action that will stop -- as soon as possible -- the violent military campaign undertaken by Israel to occupy Palestinian-controlled areas, something that is expanding day after day." 

Mubarak warned the region would experience further deterioration if Israel continued its "brutal campaign."