President Barack Obama is expected to build on diplomatic opportunities and signal his willingness to engage with the new Iranian government if Tehran makes nuclear concessions long sought by the US and Western allies.
Obama, in a planned address to the United Nations General Assembly on Tuesday, will call on UN Security Council members to approve a resolution that would mandate consequences for Syria if it fails to cooperate with a plan to turn its chemical weapons stockpiles over to the international community.
The president's address will be closely watched for signs that he may meet later in the day with Iranian President Hasan Rouhani, a moderate cleric who has been making friendly gestures toward the US in recent weeks. Even a brief encounter would be significant given that the leaders of the US and Iran haven't had face-to-face contact in more than 30 years.
US officials say no meeting was planned, though they hadn't ruled out the possibility that one might be added. The most likely opportunity appeared to be at a UN leaders' lunch Tuesday.
Rouhani was scheduled to address the UN General Assembly late Tuesday afternoon.
The possibility of a thaw in relations with Iran was expected to factor heavily in Obama's address to the UN In a preview of the president's speech, deputy national security adviser Ben Rhodes said Obama would discuss "our openness to diplomacy and the prospect for a peaceful resolution of this issue that allows Iran to rejoin the community of nations should they come in line with their international obligations and demonstrate that their nuclear program is peaceful."
The US and its allies long have suspected that Iran is trying to produce a nuclear weapon, though Tehran insists its nuclear activities are only for producing energy and for medical research.
American officials say Rouhani's change in tone is driven by the Iranian public's frustration with crippling economic sanctions levied by the US But it is still unclear whether Iran is willing to take the steps the US is seeking in order to ease the sanctions, including curbing uranium enrichment and shutting down the Fordo underground nuclear facility.
State Department officials said Secretary of State John Kerry would seek to answer that question Thursday when new Iranian Foreign Minister Mohammad Javad Zarif joins nuclear talks with the U.S. and five other world powers. Zarif's participation, which was announced Monday, sets up the first meeting in six years between an American secretary of state and anIranian foreign minister, though it was unclear whether the two men would break off from the group and hold separate one-on-one talks.
Also high on Obama's agenda at the UN was rallying Security Council support for a resolution that would establish consequences for Syrian President Bashar Assad's regime if it failed to adhere to a US-Russian plan to turn over its chemical weapons.
Under the agreement, inspectors are to be in Syria by November and all components of the chemical weapons program are to be removed from the country or destroyed by the middle of next year. The US wants the Security Council to approve a resolution making the US-Russian agreement legally binding in a way that is verifiable and enforceable.
But a key obstacle remains, given US and Russian disagreement over whether to put the resolution under Chapter 7 of the UN Charter. Chapter 7 deals with threats to international peace and security and has provisions for enforcement by military or nonmilitary means, such as sanctions. Russia is sure to veto any resolution that includes a mandate for military action.
Rhodes said Obama also would address tenuous progress in a new round of peace talks between Israelis and Palestinians. And he was to address other developments in the Arab world, including in Egypt, where the nation's first democratically elected president was ousted this summer in a coup.
A Greenpeace spokesman said: "Peaceful activism is crucial when governments around the world have failed to respond to dire scientific warnings about the consequences of climate change in the Arctic and elsewhere.
"We will not be intimidated or silenced by these absurd accusations and demand the immediate release of our activists."
Greenpeace said the activists come from Argentina, Australia, Brazil, Britain, Canada, Denmark, Finland, France, Italy, the Netherlands, New Zealand, Poland, Russia, Sweden, Switzerland, Turkey, Ukraine and the United States.