Unbowed by the failure to reach an accord to restart Mideast peace talks, President Obama told Israeli and Palestinian leaders he met Tuesday that he would keep up his administration's diplomatic efforts until negotiations are relaunched.

He then directed top foreign policy aides, including Secretary of State Hillary Rodham Clinton and special Mideast envoy George Mitchell, to continue the intense contacts with Israeli and Palestinian officials the US has pursued since Obama took office.

Mr. Mitchell said he would meet with his counterparts from both parties again Thursday, while Secretary Clinton is to report back to the president by mid-October on where diplomatic efforts stand.

"It is absolutely critical that we get this issue resolved," Mr. Obama said after a 40-minute trilateral meeting with Israeli Prime Minister Benjamin Netanyahu and Palestinian President Mahmoud Abbas.

"We cannot continue the same pattern of taking a few tentative steps forward and then stepping back," he added, noting that US national security interests are as much at stake as Israeli and Palestinian aspirations.

Obama also met separately with each leader before the trilateral meeting, which was not only the first meeting between Mr. Netanyahu and Mr. Abbas, but also the first meeting between any Israeli and Palestinian leader in a year.

Failure to reach an accord to restart peace talks was nevertheless a disappointing setback for Obama, who had hoped to use the international stage afforded by this week's United Nations General Assembly meeting to announce a breakthrough.

Some Mideast analysts say Obama is simply learning the lesson of past US presidents – that no outside power, including the United States, can force progress in resolving the conflict if the parties are not "ripe" for it.

But others say that perspective has allowed conditions to deteriorate and made achieving peace only more difficult, insisting that Obama is right to keep up American pressure.

"It's a very good thing that Obama is not giving up, but I think he is learning that this won't happen quickly and will probably take a long time," says Doron Ben-Atar, a specialist in Mideast affairs at Fordham University in New York. "At the same time it is just untrue to say that it serves no purpose for the Americans to push. When they don't, things don't just stay the same, they get worse."

The administration's insistence that all is not a waste, despite the inability to secure a restart of peace talks, is seconded by some foreign officials as not mere face-saving rhetoric.

"The time spent on these talks is not all a loss," says one senior European diplomat. For one thing, he says, "Abbas comes out of this strengthened and with greater legitimacy," while Palestinian Prime Minister Salam Fayad has used the time "doing a rather good job on investment and security."

Mitchell insisted after the trilateral meeting that substantial progress has been made, both on the ground and in bringing the two sides together, since Obama made the issue a priority of his presidency in January. Progress has been particularly strong on security issues and economic opportunity, he said.

But he acknowledged that getting from such piecemeal progress to a final peace accord will take the kind of leap forward that President Obama alluded to in his post-meeting statement. Mitchell said Obama told the two leaders that "We all must take risks for peace."

As for Israel's refusal to accept a settlement freeze for a year to allow peace talks to begin – the issue that dashed Obama's hope for a breakthrough – Mitchell said the media had made that more of a make-or-break issue than it was. At the same time, he acknowledged that the issue of settlements continues to stand in the way of a restart of peace talks.

"We have substantially progressed in reducing the differences" over settlement activity, he said, "[but] we have not reached agreement on that issue."