WASHINGTON - US Secretary of State Hillary Clinton urged Israel on Monday to make "difficult but necessary choices" for Middle East peace but promised her "rock solid" support for its security.
In an address to be delivered later in the day to the annual policy conference in Washington of the American Israel Public Affairs Committee (AIPAC), Clinton pledged that the United States would not "compromise its commitment" to prevent Israel's archfoe Iran getting a nuclear bomb.
But, according to advance excerpts of her speech, she also cautioned that a new round of UN sanctions would take time.
Clinton's speech had been keenly awaited as it comes amid one of the most difficult periods in years in US-Israeli relations as President Barack Obama's administration struggles to revive Middle East peace talks in the face of Israel's continued expansion of settlements on occupied Palestinian land.
During the day, Clinton was due to meet Israeli Prime Minister Benjamin Netanyahu, who was in Washington to deliver his own address to the key pro-Israel lobby ahead of White House talks on Tuesday.
Netanyahu has been defiant over his rightwing-led government's plans to expand Jewish settlements in annexed Arab east Jerusalem, which were announced during a visit by US Vice President Joe Biden in a way Clinton described as "insulting."
The US chief diplomat intended to "directly address the settlement issue of last week" in her talks with the Israeli prime minister, an aide said, speaking on condition of anonymity.
But US-based analysts said they doubted Netanyahu would back down on the plans because any U-turn would spell the collapse of his governing coalition -- meaning the Obama administration would likely lose face again.
The settlement expansion plans have threatened to scupper a hard-won Palestinian agreement to enter US-brokered indirect peace negotiations as a compromise on its refusal to resume direct talks without a complete freeze on all settlement construction.
US Middle East envoy met Palestinian president Mahmud Abbas in the Jordanian capital Amman on Monday in a bid to rescue the so-called proximity talks.
Mitchell said he had a "good, positive, productive" meeting on ways to start the talks at "the earliest possible time."
He said he hoped the talks would proceed "in a manner which we hope will lead to direct negotiations and an agreement that starts the process of comprehensive peace in the Middle East."
Clinton in her draft speech to the AIPAC said the path to peace "requires all parties -- including Israel -- to make difficult but necessary choices."
"The status quo is unsustainable for all sides. It promises only more violence and unrealized aspirations," she said.
Clinton promised that the drive for peace would not in any way compromise Washington's commitment to the security the Jewish state, amid mounting concern in Israel at the failure of diplomatic efforts to rein in Iran's controversial nuclear program.
"For President Obama, for me, and for this entire administration, our commitment to Israels security and Israels future is rock solid.
"Guaranteeing Israels security is more than a policy position for me. It is a personal commitment that will never waver," she said.
"In addition to threatening Israel, a nuclear-armed Iran would embolden its terrorist clientele and would spark an arms race that could destabilize the region. This is unacceptable.
"So let me be very clear -- the United States is determined to prevent Iran from acquiring nuclear weapons."
Clinton said that Washington was determined to secure agreement at the UN Security Council for a fourth round of sanctions that would show Iran's leaders that "the only choice is to live up to their international obligations."
"Our aim is not incremental sanctions, but sanctions that will bite. It is taking time to produce these sanctions, and we believe that time is a worthwhile investment for winning the broadest possible support for our efforts."
US efforts to push through a fourth set of sanctions have run into opposition from China, a veto-wielding permanent member of the Security Council with growing trade ties with Iran.
Iran rejects Western suspicions that its nuclear program is cover for a drive for a bomb, insisting its only interests are power generation and medical research.
Israel currently has the Middle East's sole if undeclared nuclear arsenal.