WASHINGTON — President Bush tried Wednesday to reassure Israelis worried about the U.S. commitment to keeping Iran from obtaining nuclear weapons.

"It's very important for the world to take Iran quite seriously," Bush told Israel's beleaguered prime minister, Ehud Olmert, at the outset of talks in the Oval Office.

Bush said they also would discuss Syria's influence in Lebanon and the Israeli government's attempts to negotiate peace with the Palestinians. As they spoke, Palestinian President Mahmoud Abbas called for a new dialogue with Hamas, the militant group that has taken control of the Gaza Strip from Abbas' government. Abbas said he will call for new legislative and presidential elections if the talks succeed.

Neither Bush nor Olmert mentioned perhaps the most pressing issue for their talks: Olmert's deteriorating political situation back home, where his popularity has nose-dived because of a new corruption scandal, and the end of his term is largely seen as just a matter of time. The developments are jeopardizing Bush's already ambitious timetable for an Israeli-Palestinian peace agreement by year's end and are making it unlikely that Bush or Olmert will be able to shepherd the process to completion.

For Olmert, a friendly meeting with a stalwart ally like Bush was a marked change from what he left behind in Israel, where his political allies are conspicuously refusing to come to his defense and jostling for his job. The Israeli leader seemed delighted to be again at the side of Bush, who is enormously popular in Israel. Olmert smiled broadly at Bush throughout his opening remarks and effusively praised his speech last month before the Israeli Knesset.

"It was the best example of the United States' commitment to the security and world view of the state of Israel," Olmert said.