US Energy Secretary Ernest Moniz says Washington would lift all sanctions imposed against Iran only when Tehran complies with the core nuclear restrictions.
"On sanctions, I'll make it very, very clear: The sanction relief really kicks in only when they have complied with the core nuclear restrictions, Moniz said in an interview with CBS on Sunday.
And that's what gets us to this two-month to one-year breakout time. So that's when the sanctions relief will really kick in," he added.
On Thursday, the P5+1 group the US, Britain, France, China, Russia and Germany reached an outline of a potentially historic agreement with Iran over Tehrans nuclear energy program.
[caption id="" align="alignnone" width="550"] From left: US Energy Secretary Ernest Moniz, US Secretary of State John Kerry, his Iranian counterpart Mohammad Javad Zarif and the head of the Iranian Atomic Energy Organization Ali Akbar Salehi[/caption]
At the end of eight days of intense nuclear negotiations in the Swiss city of Lausanne, Iran and the world powers issued a joint statement, saying that no Iranian nuclear facility will be shut down and that Iran will continue with its nuclear activities in all its nuclear facilities, including Natanz, Fordow, Isfahan and Arak.
President Barack Obama hailed the "historic understanding" with Iran, saying that it paves the way for a final agreement in three months.
Several Republicans, however, have slammed the nuclear understanding, saying lifting sanctions on Iran would provoke Israel into an armed conflict with Tehran.
On March 29, US House of Representatives Speaker John Boehner vowed to impose more sanctions on Iran should Obama fail to reach an agreement.
Iran and the P5+1 group of countries have set June 30 as the final deadline for a comprehensive deal.