Israeli Prime Minister Ehud Olmert arrived in Washington Sunday for a five-day trip that will focus largely on Iran's nuclear program and Israel's volatile relations with the Palestinians.

The visit comes one day after the U.S. vetoed a Security Council resolution that would have condemned Israel's military campaign in the Gaza Strip and demand Israel withdraw from the territory.

John Bolton, the U.S. ambassador to the UN, described the draft as biased and politically motivated.

During the flight to Washington, Olmert used strong language when referring to Iran, warning the nation will not reign in its nuclear program unless it fears repercussions.

"They have to be afraid of the consequences if there isn't a compromise," spokeswoman Miri Eisin cited Olmert as telling journalists on the flight.

However, Olmert seemed to play down comments made by Deputy Defense Minister Ephraim Sneh, who said Israel was preparing a pre-emptive strike against Iran's nuclear program.

Olmert said "we have to be very careful about what we say," according to Eisin.

Israel maintains that Iran is developing nuclear weapons, a charge Tehran denies.

Iranian President Mahmoud Ahmadinejad has repeatedly called for Israel's destruction, but maintains the nuclear program is meant solely to produce energy.

The war of words between the two nations appears to be ramping up recently. On Sunday, Iran's foreign ministry pledged Iran would respond to Israeli military action with "swift, strong and crushing" action.

The increasing tensions were to be the main item on Olmert's Washington agenda, he said ahead of the meetings.

The schedule has Olmert meeting with Secretary of State Condoleezza Rice on Sunday and President Bush on Monday.

Analysts believe Israel is worried that the Americans' traditionally tough stance against Iran could weaken with the Democratic election victory last week. With U.S. public opinion turning against the Iraq war, the worry is that Bush would be less inclined to take military or diplomatic action against Iran.

Some also worry Bush might be willing to end the policy of isolating Iran in return for a compromise with the armed groups in Iraq that Iran has influence over.

Olmert is also expected to spend some time discussing the Palestinian conflict. However, he was quoted as saying "this isn't a dramatic visit" and major changes were unlikely to take place.

With files from The Associated Press