The war of words over whether an American president should negotiate with sponsors of terrorism escalated Friday as John McCain took Barack Obama to task for saying earlier in the day that McCain and President Bush were fear-mongering by questioning such diplomacy.

"Senator Obama would meet unconditionally with some of the world's worst dictators and state sponsors of terrorists. I would not add to the prestige of those who support violent extremists or seek to destroy our allies," McCain said at a meeting of the National Rifle Association in Louisville, Ky.

"It is reckless ... it is reckless to suggest unconditional meetings will advance our interest," he said.

McCain was aligning himself more closely with Bush, who touched off the foreign policy firestorm Thursday when, during an address to the Israeli Knesset, he criticized politicians who would negotiate with "terrorists and radicals" and compared that approach to the appeasement of the Nazis prior to World War II .

Though Bush did not name Obama, who has said he would meet with nations like Iran without preconditions, Democrats quickly accused the president of a broadside attack on their front-running presidential candidate.

On Friday, Obama said Bush's words were "exactly the kind of appalling attack that's dividing our country and that alienates us from the world."

The Democratic front-runner then accused McCain of teaming up with Bush to launch "dishonest, divisive" attacks on his foreign policy platform.

Obama spoke while campaigning in South Dakota, which holds its Democratic primary on June 3. His speech underscored how he is looking ahead to the general election. With Bush's approval rating very low in most national polls, Obama seized every opportunity to lump McCain in with the president and his policies.

"George Bush and John McCain have a lot to answer for," Obama said, ticking off grievances ranging from the billions spent on the Iraq war to the thousands of Americans who have been killed there.

"That's the Bush-McCain record on protecting this country. Those are the failed policies that John McCain wants to double down on, because he still hasn't spelled out one substantial way he'd be different from George Bush when it comes to foreign policy."

Obama accused McCain of "fear-peddling" and of embracing Bush's comments the day before during his Knesset address.

McCain spokesman Tucker Bounds fired back Friday that Obama's retort was a "hysterical diatribe in response to a speech in which his name wasn't even mentioned."

"Unconditional meetings with the man who calls Israel a stinking corpse and arms terrorists who kill Americans will not convince Iran to give up its nuclear program," McCain said later Friday.

Obama stressed Friday in South Dakota that he would never enter into direct talks with terrorist groups like Hamas.

Later, at a news conference, Obama said he was offended by Bush's comments and argued that Republican and Democratic presidents, such as John Kennedy, Richard Nixon and Ronald Reagan, had engaged in direct talks with U.S. foes.

Obama also accused McCain of "hypocrisy," after former State Department official James Rubin wrote in a Washington Post column that McCain said two years ago of Hamas: "They're the government; sooner or later we are going to have to deal with them."

McCain insisted Friday he would not negotiate with terrorists and defended his criticism of Obama.

"I say again, Barack Obama wants to sit down with their sponsors. If he doesn't want to sit down with Hamas then he shouldn't want to sit down with their sponsor," McCain said.

McCain gave no objection to Bush's comments Thursday and said Obama's approach to foreign policy was fair game for questioning.

Bush said Thursday: "Some seem to believe that we should negotiate with the terrorists and radicals, as if some ingenious argument will persuade them they have been wrong all along.

"We have heard this foolish delusion before. As Nazi tanks crossed into Poland in 1939, an American senator declared: ‘Lord, if only I could have talked to Hitler, all of this might have been avoided.'

"We have an obligation to call this what it is -- the false comfort of appeasement, which has been repeatedly discredited by history."

Ed Gillespie, counselor to the president, said Friday the White House was taken aback by the backlash that followed Bush's speech.

"We did not anticipate that it would be taken that way, because it's kind of hard to take it that way if you look at the actual words of the president's remarks, which are consistent with what he has said in the past relative to dealing with groups like Hezbollah and Hamas and Al Qaeda," Gillespie said.

"And so there was really nothing new in the speech that anyone could point to that would indicate that."

He said there was some anticipation that it would be seen as a slam against former President Jimmy Carter, who recently met with leaders of Hamas, but that it was not intended as a rebuke to him, either.

FOX News' Major Garrett and Shushannah Walshe and The Associated Press contributed to this report.