Democratic presidential frontrunner Barack Obama said Friday that President George W. Bush's policies in the Middle East have served to benefit U.S. foes Iran and Hamas.

"[Bush and Republican nominee John McCain have] got to answer for the fact that Iran is the greatest strategic beneficiary of our invasion of Iraq. It made Iran stronger, George Bush's policies," he said.

"They're going to have to explain why Hamas now controls Gaza, Hamas that was strengthened because the United States insisted that we should have democratic elections in the Palestinian Authority," he added.

Obama, relishing a long-distance debate with Bush on foreign policy, said the president had contributed to Tehran's rise in the Middle East by launching the Iraq war, which he said had removed Baghdad as a counterweight to Iran.

The Illinois senator said Republican presidential nominee John McCain was as much to blame as Bush for what he termed a failure of U.S. policy in the Middle East.

"They're trying to fool you, and trying to scare you, and they're not telling the truth. And the reason is because they can't win a foreign policy debate on the merits. But it's not going to work," said Obama, the Democratic front-runner vying to face McCain in the November presidential election.

Speaking to reporters after a speech, Obama said if elected president he would meet, with preparation but without preconditions, leaders Bush has avoided - Iranian President Mahmoud Ahmadinejad, Syrian President Bashar al-Assad, North Korea's Kim Jong-il and Venezuelan President Hugo Chavez.

"I would engage in direct talks," he said.

Iran, Syria and North Korea are considered by the U.S. State Department to be state sponsors of terrorism while Venezuela has stoked anti-American sentiment in South America.

Obama accused Bush on Friday of "fear-mongering" for suggesting Democrats wanted to appease terrorists and vowed to meet leaders of hostile nations like Iran if elected.

Bush triggered Democratic outrage on Thursday by saying in a speech before the Knesset in Jerusalem that some politicians would pursue the "false comfort of appeasement" by negotiating with militant groups like Hamas and Hezbollah organizations and Iran.

Obama said Bush and McCain were guilty of "bombast, exaggerations and fear-mongering."

The White House said it was baffled at the heat of the Democratic response, saying Bush had been making similar statements for years.

"I would encourage you to ask them what sentences that they disagree with, what specific sentence," White House counselor Ed Gillespie said on the Air Force One flight to Saudi Arabia.

The McCain campaign derided Obama for what it called "the same tired partisan rants."

"It was remarkable to see Barack Obama's hysterical diatribe in response to a speech in which his name wasn't even mentioned," said McCain spokesman Tucker Bounds.

The episode allowed Obama to talk directly to Bush and elevate himself on the national stage as he tried to wrap up the Democratic presidential nomination. Even party rival Hillary Clinton has rushed to Obama's defense on the issue.

Weakened by the Iraq war and ailing economy, Republicans hope to convince Americans that Obama is too inexperienced to be trusted as commander in chief - a point McCain tried to make on Thursday.

But Obama sought to turn the experience question around on Bush and McCain.

"They've got to answer for the fact that Iran is the greatest strategic beneficiary of our invasion of Iraq. It made Iran stronger, George Bush's policies," he said.

"They're going to have to explain why Hamas now controls Gaza, Hamas that was strengthened because the United States insisted that we should have democratic elections in the Palestinian Authority," he added.