Iran will be allowed to continue operating 5,000 nuclear centrifuges under any final accord reached by negotiators, Western sources who fear a bad Iran nuclear deal told The Washington Free Beacon.

Iran and Western powers have reportedly already reached a deal in which Iran will be allowed to continue to run 5,000 centrifuges which are capable of enriching uranium to necessary levels needed to make a nuclear weapon.

The State Department announced on Tuesday that the self-imposed June 30 deadline to reach a final deal will be extended until at least July 7 in order to provide more time for negotiators to reach a long-term solution, CNN reported. If Iran agrees to not pursue the development of nuclear weapons, negotiators are expected to provide significant economic sanctions relief to the country.

Part of that delay may be due to reports that Iranian leaders have demanded that the U.S. agrees to allow the country to continue operating its core nuclear structure, including the 5,000 centrifuges and other nuclear research efforts, according to the Beacon.

Experts fear that 5,000 centrifuges could enable Tehran to enrich enough uranium for several bombs. Countries such as Pakistan and North Korea have reportedly produced nuclear weapons with far fewer centrifuges.

"Iran is poised to walk away from Vienna with more centrifuges than North Korea has ever been known to possess and a U.S.-endorsed R&D program to improve their efficiency," Chris Griffin, executive director of the Foreign Policy Initiative, told the Beacon. "For talks that began with U.S. officials insisting that Iran dismantle its enrichment capability, that outcome will mark a resounding collapse."

Others, like former CIA deputy director Michael Morrell, say 5,000 is the number you need.

"If you are going to have a nuclear weapons program, 5,000 is pretty much the number you need," Morell told CBS in February, according to PolitiFact. "If you have a power program, you need a lot more. By limiting them to a small number of centrifuges, we are limiting them to the number you need for a weapon."

And that's the difficult part: determining whether Iran is using its centrifuges to pursue nuclear weapons, or using them to develop nuclear power for non-threatening civilian uses. Iran says it is only involved in the latter.

Another source present in Vienna for the nuclear negotiations told the Beacon: "It is alarming to see how in dealing with this regime in Tehran, our negotiators have learned so little from past errors, where leaving nuclear infrastructure, like thousands of centrifuges, in the hands of lying, terror-sponsoring, human rights abusing, ballistic missile shooting mad-men resulted in nuclear weapons and proliferation, just as this bad deal will promote."

President Obama threatened again on Tuesday to "walk away" from a nuclear deal with Iran that would allow it to develop nuclear weapons, Fox News reported.

"My hope is they can achieve an agreement," Obama said during a joint press conference in Washington with visiting Brazilian President Dilma Rousseff. "I've said from the start, I will walk away from the negotiations if in fact it's a bad deal."