Democratic presidential contender and presumptive Republican presidential nominee John McCain squared off over Obama's willingness to meet with enemies of the United States in a series of exchanges Friday.

“George Bush and John McCain have a lot to answer for,” Obama said in Waterton, South Dakota, Friday morning. “If George Bush and John McCain want to have a debate about protecting the United States of America, that is a debate I am happy to have any time, any place,” Obama said.

“They’re trying to fool you,” Obama charged. “They’re trying to scare you. And they’re not telling you the truth. And the reason is that they can’t win a foreign policy debate on the merits.”

Obama also reiterated this promise to meet with hostile nations. “I believe we need to use all elements of American power to pressure Iran—including tough, principled and direct diplomacy,” Obama said.

Just a few hours after Obama wrapped his presser McCain fired back from the National Rifle Association's national conference in Louisville, Kentucky. "I have some news for Senator Obama: Talking, not even with soaring rhetoric, in 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. It is reckless to suggest that unconditional meetings will advance our interests," McCain said.

The Obama campaign believes President Bush engaged in “extraordinary politicization of foreign policy” in an address before the Israeli Knesset Thursday to celebrate Israel’s 60th birthday. In that speech Bush said, “Some seem to believe we should negotiate with 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.”

On the campaign trail, Obama has said repeatedly that he would meet with “friends and foes” of the United States if elected president in November. In a televised debate he said he would meet with foreign nations without “preconditions.”

The White House contends the statement was not specifically geared towards Obama, but captures the sentiments of many liberally-leaning Americans like Jimmy Carter.

In a conference call with bloggers after Bush’s speech, McCain continued the line of attack about Obama’s diplomacy preferences. McCain said he would “welcome” a debate with Obama about this. “I think it is an unacceptable position and shows Senator Obama does not have the knowledge, the experience, the background to make the kind of judgments that are necessary to preserve this nation,” McCain said.