(CNN) -- As an interim nuclear deal between Iran and world powers goes into effect Monday, Tehran plans to start eliminating its higher levels of enriched uranium in a few hours, the Fars news agency reported.
The six-month interim agreement gives Iran and six other countries -- the United States, Britain, China, France, Russia and Germany -- more time to negotiate a permanent solution.
Iran struck the deal in November in exchange for lighter sanctions from Western nations.
As part of the agreement, it must eliminate its stockpile of higher levels of enriched uranium, dismantle some infrastructure that makes enrichment possible and allow international inspections of its programs.
"This is an important day in our pursuit of ensuring that Iran has an exclusively peaceful nuclear program," said Catherine Ashton, the European Union foreign policy chief.
She said she's optimistic a new round of negotiations could come soon.
"Depending on how things work out today, I hope that we will start talks in the next few weeks," Ashton said.
If all conditions are met, Iran will get sanctions relief totaling about $7 billion, including access to $4.2 billion in frozen assets, during the six months the interim deal is in effect.
For years, Iran and Western powers have left negotiating tables in disagreement, frustration and open animosity.
The diplomatic tone changed last year when President Hassan Rouhani took over after winning the elections.
And the deal appeared to be on the right track Monday.
Iran said it will start eliminating its stockpile of higher levels of enriched uranium in the next several hours, the semiofficial Fars News agency reported. It cited Behrouz Kamalvandi, the spokesman for Atomic Energy Organization of Iran.
The spokesman said the process was delayed because the final stage of talks between inspectors and Iranian officials was still ongoing.
As part of the deal, Iran was required to dilute its stockpile of uranium that had been enriched to 20%.
While uranium isn't bomb-grade until it's enriched to 90% purity, "once you're at 20%, you're about 80% of the way there," said Mark Hibbs, a nuclear policy expert at the Carnegie Endowment for International Peace.
The deal also mandates Iran halt all enrichment above 5% and dismantle the technical equipment required to do that.
Iran consistently says it's enriching uranium and building nuclear reactors only for peaceful civilian energy needs. Nuclear power plants use uranium that is enriched to 5%. It's the fuel that the plants use to generate electricity.
World leaders applauded the interim deal after years of a stalemate.
"For the first time in nearly a decade, we have halted the progress of the Iranian nuclear program," U.S. President Barack Obama said when the deal was announced in November.