WASHINGTON (CNN) -- Sen. Barack Obama vowed Wednesday that Jerusalem must "remain the capital of Israel, and it must remain undivided."
"Any agreement with the Palestinian people must preserve Israel's identity as a Jewish state, with secure, recognized and defensible borders," the presumptive Democratic presidential nominee said at the annual conference of the American Israel Public Affairs Committee, an influential pro-Israel lobbying group.
"Jerusalem will remain the capital of Israel, and it must remain undivided," Obama said.
The Palestinians also want Jerusalem to be the capital of their own country. United States policy has long been intentionally vague on the status of Jerusalem. The U.S. Embassy in Israel is in Tel Aviv, not Jerusalem.
Obama opened his speech to AIPAC by paying tribute to his rival, Sen. Hillary Clinton, calling her an extraordinary public servant who had made history alongside him in their 16-month race for the party's presidential nomination. Watch more of Obama's AIPAC speech »
Obama clinched the nomination Tuesday night, but Clinton did not admit defeat in her speech after the polls closed.
Obama called Iran the greatest threat in the Middle East, but reiterated his willingness to meet with the Islamic state's leaders under appropriate conditions.
"Contrary to the claims of some, I have no interest in sitting down with our adversaries just for the sake of talking. But as president of the United States, I would be willing to lead tough and principled diplomacy with the appropriate Iranian leader at a time and place of my choosing -- if, and only if it can advance the interests of the United States," Obama said.
John McCain, the presumptive Republican presidential nominee, has repeatedly criticized Obama for saying he would be willing to meet with the leaders of hostile nations.
Obama, for his part, blasted McCain's Iraq policy.
"Sen. McCain offers a false choice: Stay the course in Iraq, or cede the region to Iran. I reject this logic because there is a better way. Keeping all of our troops tied down indefinitely in Iraq is not the way to weaken Iran -- it is precisely what has strengthened it," Obama said.
But the Democrat denied he would pull U.S. troops out of Iraq without taking into account conditions on the ground, as McCain has charged.
"I have proposed a responsible, phased redeployment of our troops from Iraq. We will get out as carefully as we were careless getting in. We will finally pressure Iraq's leaders to take meaningful responsibility for their own future," he said.
Clinton spoke immediately after Obama at the conference and praised him, saying he would be a friend to Israel.
Though Clinton has yet to concede the Democratic race and spoke Wednesday of what she would do as president, she told AIPAC that Obama "understands what is at stake here."
"It has been an honor to contest these primaries with him. It is an honor to call him my friend. And let me be very clear: I know that Sen. Obama will be a good friend to Israel," the New York senator and former first lady said. Watch more of Clinton's speech »
Some Clinton supporters have begun to campaign for Obama to choose Clinton as his running mate, but the two campaigns deny that discussions on the subject have begun.
Obama also directly addressed accusations that have been circulating by e-mail.
"I want to say that I know some provocative e-mails have been circulating throughout Jewish communities across the country," Obama said.
"They're filled with tall tales and dire warnings about a certain candidate for president. And all I want to say is -- let me know if you see this guy named Barack Obama, because he sounds pretty scary."
Rumors have been circulating at least since last year that Obama is a Muslim and does not support the Jewish state. He is a Christian and said at the conference he is a "true friend of Israel," earning applause.
In his AIPAC speech, Obama also clarified a story he told last month that prompted a barrage of criticism from Republicans.
"My great uncle had been a part of the 89th Infantry Division -- the first Americans to reach a Nazi concentration camp. They liberated Ohrdruf, part of Buchenwald, on an April day in 1945," Obama said.
Last month, he said an uncle had helped liberate the Auschwitz concentration camp, which was in fact liberated by the Soviet army.