New York:
He's hardly the first president to come this podium seeking Mideast peace, but Barack Obama is hoping against hope to be the last.
"Now is the time for this opportunity to be seized, so that it doesn't slip away," he says.
In his annual general assembly speech, he said he wants next year's to herald the seating of an independent Palestinian state.
But peace talks that resumed three weeks ago have hit a familiar wall: Jewish settlements. Israel's balked at continuing a partial building freeze. Palestinians say without it, talking's a waste of time.
"We believe that the moratorium should be extended. We also believe that talks should press on until completed," said the US President.
Palestinian officials observed Obama on in studied silence while Isreal's were absent for the Jewish holiday.
But the president also implored friends of the two sides to help them make touch choices. For Arab countries his message was especially blunt: don't just pay peace lip service, and don't think you help Palestinians by tearing Israel down.
To Iran, possibly China-India and close.
"The Iranian government must demonstrate a clear and credible commitment, and confirm to the world the peaceful intent of its nuclear program," said Obama.
Apparently, Iran's leader didn't get the memo. He accused Israel of "horrible crimes" against the Arabs -- and said Tehran will host a conference next year on allegations that Jews masterminded 9/11.
At that the US delegation walked out.
Meantime, Obama was making the diplomatic rounds, addressing the Clinton Global Initiative and pressing his case with China's leader that Beijing's currency is still hugely and unfairly undervalued, harming US exports.
Aides report there was plenty of frank talk on this, but no resolution.