Iran is showing willingness to make concessions in exchange for the lifting of economic sanctions in negotiations over its nuclear capabilities.

According to The Wall Street Journal, Iranian officials said Monday that they are "willing to accept" a reduction in their nuclear enrichment capabilities for the duration of the nuclear agreement.

Tehran is also weighing other options, but the current proposal is not likely to be accepted by the West. It is the first time Iran has shown flexibility on the issue of its nuclear enrichment plan.

According to an Iranian and Western diplomat who spoke to the Journal on condition of anonymity, Iran is suggesting freezing the number of centrifuges it operates at 9,400. It is also proposing reducing the fuel it produces from the machines by spinning them more slowly during the period of the nuclear deal, which will be years.

Iran first mentioned the proposal to European diplomats a few weeks ago.

While the proposal will reduce Iran's capabilities, it is unlikely to be accepted by the West because it would not significantly reduce the enrichment program. Under Iran's proposal, Tehran could easily renege by increasing the output of the centrifuges once again.

Regardless, the proposal is a big step for Iran, as the country's supreme leader, Ayatollah Ali Khamenei, has been demanding that the West allow Tehran to increase its nuclear program.

The deadline for reaching a deal is quickly approaching, as it must be struck by July 20. Iran's proposal could help extend negotiations.

U.S. Secretary of State John Kerry, who is in Vienna negotiating with Iranian Foreign Minister Javad Zarif, said this month that Washington will extend the talks only if Iran shows it is willing to compromise.

Kerry and Zarif met for two hours Monday morning after they had held discussions in Vienna on Sunday. The two then continued discussions later Monday.

As of Monday morning, an official from the U.S. State Department said Kerry can stay in Vienna to continue talks and "see if progress can be made."

Iran is negotiating with the U.K., China, Russia, France and Germany, in addition to the U.S., to strike a nuclear deal. However, Iran insists that its nuclear program is intended for peaceful purposes.

If an agreement is reached, the West will lift sanctions on Iran if Tehran ensures that it will not produce enough nuclear fuel to create an atomic bomb.

U.S. officials have said Iran will be able to operate a bigger enrichment program, but strictly for peaceful purposes, after the multiyear nuclear deal expires.

While the Iranian proposal is a start, both sides differ on the details of the agreement, as well as how many years the agreement will last.

While the U.S. wants the deal to last for up to 20 years, Iran believes it should last only a few years at most.

U.K. Foreign Secretary William Hague said Sunday there is a "huge" discrepancy between Iran and Western powers on the nuclear deal. And during the talks, Western officials said Iran was talking about amping up its nuclear output.

As of now, "Iran has around 19,000 centrifuges, all but 1,000 of which are old-generation" centrifuges, which have low enrichment capabilities. Only 9,400 of them are operating and producing nuclear fuel at the Natanz nuclear facility in Tehran.

According to the Iranian proposal, none of the centrifuges would be removed from Natanz, including the thousands of centrifuges that are not operating, in addition to the more advanced centrifuges.