WASHINGTON (AP) President Bush pledged yesterday to help end the Mideast"s "tragic cycle of incitement, provocation and violence," telling the Palestinians to stop their killing and urging restraint from the Israeli military. But he said he won"t try to force a settlement.

In an impromptu news conference mixing domestic and foreign policy, the president also told Congress it must not bypass his massive 10-year tax cut in a rush to short-term reductions and promised to reduce the arsenic levels of U.S. drinking water.

In a 30-minute session shortly before meeting German Chancellor Gerhard Schroeder, Bush pre-empted his visitor by rejecting calls by Germany and other allies to back a global warming treaty. "We will not do anything that harms our economy," he said.

It was the new president"s second full-scale news conference and, like the first, came with little notice. Advisers say Bush hopes to avoid formal, prime-time news conferences from the White House East Room with their accompanying buildup of expectations.

He seemed to enjoy the session yesterday, joshing with reporters who tried to interrupt his answers and pardoning one whose beeper sounded. When Bush said Americans might "misunderestimate" his tax plan, he corrected himself with a chuckle.

"Excuse me. Underestimate," he said. "Just making sure you were paying attention."

Bush spoke as fresh clashes and harsh rhetoric scarred the Middle East. A defiant Yasser Arafat said the Palestinian uprising will continue despite Israel"s warnings, which were delivered a day earlier with rocket attacks on the bases of Palestinian forces.

Bush has been urging both sides to end the violence but his actions have been subdued, in contrast to former President Clinton who personally mediated failed peace talks.

Bush"s remarks yesterday seemed to signal a more assertive, direct role in the Middle East though his outline of U.S. policy still stressed rhetoric over personal diplomacy.

He urged Palestinian leaders to speak out against violence and suggested that Arafat won"t be invited to the White House along with other regional leaders until he does so "in a language that the Palestinians can understand."

"The signal I am sending to the Palestinians is stop the violence," Bush said. "I hope that Chairman Arafat hears it loud and clear."