WASHINGTON -- President Barack Obama says his administration's approach to Syria's chemical weapons should show Iran that there's the potential for diplomatic solutions to arms standoffs.

But he says Iran shouldn't assume that his preference for diplomacy means the U.S. won't strike Tehran.

Obama tells ABC's "This Week" that Iranians understand that their pursuit of a nuclear weapon is "a far larger issue for us" than the use of chemical weapons in Syria.

Obama says he has exchanged letters with Iran's new president, but the two have not spoken directly.

Obama says he believes Iranian President Hasan Rouhani (hah-SAHN' roh-HAH'-nee) understands the potential for a diplomatic solution to his country's disputed nuclear program but will not "suddenly make it easy."

Iran says its nuclear program is for peaceful purposes.

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  • Susan Rice

    "All of this is horrific. All of us as human beings feel terrible when we see the extraordinary loss of life that [has] occurred in Syria," Rice said. "With chemical weapons, they can kill with indiscriminate abandon. People who are innocent are employed in conflict. It is of a greater magnitude because if terrorists get ahold of those weapons, if other dictators get ahold of those weapons, they can be used on a massive scale."

  • John Boehner

    "We have enemies around the world that need to understand that we're not going to tolerate this type of behavior."

  • John McCain

    "I am against delaying reaction to what is a massacre of a thousand people," McCain said. "You saw these pictures of these dead children. Come on. This is horrific. We can't stand by and watch this happen."

  • John Kerry

    "This is what Assad did to his own people," Kerry said. If the U.S. allowed "a thug and a murderer like Bashar al-Assad" to get away with gassing his own people, he added, "there will be no end to the test of our resolve and the dangers that will flow from those others who believe that they can do as they will."

  • Rand Paul

    "I think the Islamic rebels winning is a bad idea for the Christians, and all of a sudden we'll have another Islamic state where Christians are persecuted," Paul said.

  • Sarah Palin

    "As I said before, if we are dangerously uncertain of the outcome and are led into war by a Commander-in-chief who can’t recognize that this conflict is pitting Islamic extremists against an authoritarian regime with both sides shouting 'Allah Akbar' at each other, then let Allah sort it out," Palin continued.

  • Ted Cruz

    “We should be focused on defending the United States of America. That’s why young men and women sign up to join the military, not to, as you know, serve as Al Qaeda’s air force.”

  • Barack Obama

    "This attack is an assault on human dignity. It also presents a serious danger to our national security. It risks making a mockery of the global prohibition on the use of chemical weapons. It endangers our friends and our partners along Syria’s borders, including Israel, Jordan, Turkey, Lebanon and Iraq. It could lead to escalating use of chemical weapons, or their proliferation to terrorist groups who would do our people harm. "In a world with many dangers, this menace must be confronted."

  • Bob Menendez

    "Assad has made a calculation now ... that he can use chemical weapons, or he believes he can use chemical weapons without consequence," Menendez said. "And in doing so there is a global message that in fact other state actors and other non-state actors may believe they can do so as well."