Israeli Prime Minister Benjamin Netanyahu says his country was crucial in preventing global powers and Iran from signing what he says would have been a "bad deal" on Tehran's nuclear program last month.
The global powers known as the P5+1 have extended their talks with Tehran until June 30, after they failed to meet the November 24 deadline for a deal.
The West wants Iran to scale down nuclear activities, such as uranium enrichment, to ensure it cannot produce nuclear weapons.
Iran denies trying to develop such weapons.
Netayahu told a Washington conference in a recorded address that had an agreement been reached by November 24, it would have "effectively left Iran as a threshold nuclear power."
He said Israel's "voice and our concerns played a critical role in preventing a bad deal."
Addressing the same conference, U.S. Secretary of State John Kerry urged patience while vowing that the process wold not continue without "tangible progress."