Prime Minister Benjamin Netanyahu of Israel told the United Nations on Thursday that Iran’s capability to enrich uranium must be stopped before next spring or early summer, arguing that by that time the country will be in a position to make a short, perhaps undetectable, sprint to manufacture its first nuclear weapon.

In his speech at the annual General Assembly, Mr. Netanyahu dramatically illustrated his intention to shut down Iran’s nuclear program by drawing a red line through a cartoonish diagram of a bomb. But the substance of his speech suggested a softening of what had been a difficult dispute with the Obama administration on how to confront Iran over its nuclear program.

Only two weeks after that dispute broke into the open, Mr. Netanyahu on Thursday praised the warning Mr. Obama gave Iran in his own General Assembly speech on Tuesday.

“I very much appreciate the president’s position, as does everyone in my country,” he said. The Israeli leader’s speech also suggested that his deadline for a military strike was well past the American presidential election and into 2013 — perhaps as late as next summer.