S enior Israeli officials are acknowledging that some enriched uranium may have survived the powerful U.S. strikes on Iran's key nuclear sites last month.

The process of uranium enrichment increases the concentration of U-235, an isotope that can sustain a nuclear chain reaction. Beginning in 2006, the U.N. Security Council called on Iran to suspend all uranium enrichment, but it endorsed the JCPOA on July 20, 2015.

Israeli Prime Minister Benjamin Netanyahu claims Iran will not pursue nuclear weapons following U.S. and Israeli strikes, stating Tehran is afraid after feeling "the might of America and Israel."

Israeli Prime Minister Netanyahu meets with President Trump to discuss Iran strikes, Gaza conflict and Abraham Accords amid new era of U.S.-Israel strategic partnership

The appraisal that Iran’s nuclear hopes had been set back 1 to 2 years by U.S. and Israeli bombings was the latest in a shifting series of pronouncements.

The Pentagon on Wednesday sharpened its assessment of Iran's nuclear program, declaring that Iran's ability to build a nuclear weapon following the U.S. strike on its nuclear facilities is "closer to two years" away.

US airstrikes on Iran set back the regime’s nuclear program between one to two years, but likely “closer to two,” the Pentagon’s top spokesperson said Wednesday. “Our assessment of the battle damage around Fordow, Natanz and Isfahan remains unchanged,” Pentagon spokesman Sean Parnell told reporters during a press briefing.

CIA Director John Ratcliffe has told skeptical U.S. lawmakers that American military strikes destroyed Iran’s lone metal conversion facility and delivered a monumental setback to Tehran’s nuclear program that will take years to overcome.

<p>News about Iran&#8217;s nuclear program, including commentary and archival articles published in The New York Times.</p>

The intelligence community has not finalized its battle damage assessment for the effects of the U.S. military's strikes on three of Iran's nuclear facilities.