Foremost among these should be curbing the Iranian nuclear threat, the former Israeli prime minister said, followed by "reinvigorating" the Palestinian peace process.
"They clearly bear most of the responsibility for past failures," Barak said of the Palestinian leadership. "I know a fully-fledged agreement is probably not feasible today … [but] as our sages teach us, if not now, when?"
Barak also highlighted issues of border security and missile defense he said need further attention.
The AIPAC policy conference is the largest gathering of Israel supporters in the United States.
It regularly draws speeches from administration officials, top level diplomats and presidents. Obama spoke in 2012, but will be represented by Vice President Joe BidenJoe BidenBiden: 'McCain is right: Need select committee' for Russia With no emerging leaders, no clear message, Democrats flounder Obama defends healthcare law on eve of repeal vote MORE this year.
Barak is scheduled to meet Tuesday with Hagel, whom he has known for more than a decade. Per reports, their agenda will include the threat posed by Iran and the sequester's effect on U.S. aid to Israel.
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